diff --git a/mypy/main.py b/mypy/main.py
index 0cf624a3a5d7b..e16a59c6fdb13 100644
--- a/mypy/main.py
+++ b/mypy/main.py
@@ -1296,10 +1296,10 @@ def add_invertible_flag(
         dest="local_partial_types",
         help=argparse.SUPPRESS,
     )
-    # --native-parser enables the native parser (experimental)
+    # --native-parser enables the native parser.
     add_invertible_flag(
         "--native-parser",
-        default=False,
+        default=True,
         help="Enable faster parser that parses directly to mypy AST",
     )
     # --logical-deps adds some more dependencies that are not semantically needed, but
diff --git a/mypy/options.py b/mypy/options.py
index 92c9ea3b1701d..88f8e674ed2e7 100644
--- a/mypy/options.py
+++ b/mypy/options.py
@@ -385,8 +385,8 @@ def __init__(self) -> None:
         self.logical_deps = False
         # If True, partial types can't span a module top level and a function
         self.local_partial_types = True
-        # If True, use the native parser (experimental)
-        self.native_parser = False
+        # If True, use the native parser
+        self.native_parser = True
         # Some behaviors are changed when using Bazel (https://bazel.build).
         self.bazel = False
         # If True, export inferred types for all expressions as BuildResult.types
diff --git a/mypy/test/testfinegrained.py b/mypy/test/testfinegrained.py
index 8a93018e39b32..809386117eb37 100644
--- a/mypy/test/testfinegrained.py
+++ b/mypy/test/testfinegrained.py
@@ -44,6 +44,8 @@
 )
 
 # Set to True to perform (somewhat expensive) checks for duplicate AST nodes after merge
+from mypy.test.update_data import update_testcase_output
+
 CHECK_CONSISTENCY = False
 
 
@@ -130,6 +132,10 @@ def run_case(self, testcase: DataDrivenTestCase) -> None:
         # Normalize paths in test output (for Windows).
         a = [line.replace("\\", "/") for line in a]
 
+        # This may not work perfectly, since it was designed for testcheck.py, use with care.
+        if testcase.output != a and testcase.config.getoption("--update-data", False):
+            update_testcase_output(testcase, a, incremental_step=1)
+
         assert_string_arrays_equal(
             testcase.output, a, f"Invalid output ({testcase.file}, line {testcase.line})"
         )
diff --git a/mypy/test/testparse.py b/mypy/test/testparse.py
index 8f4de5bc7412b..3d4de307b7ad5 100644
--- a/mypy/test/testparse.py
+++ b/mypy/test/testparse.py
@@ -13,6 +13,7 @@
 from mypy.parse import parse
 from mypy.test.data import DataDrivenTestCase, DataSuite
 from mypy.test.helpers import assert_string_arrays_equal, find_test_files, parse_options
+from mypy.test.update_data import update_testcase_output
 from mypy.util import get_mypy_comments
 
 
@@ -115,6 +116,11 @@ def test_parse_error(testcase: DataDrivenTestCase) -> None:
     except CompileError as e:
         if e.module_with_blocker is not None:
             assert e.module_with_blocker == "__main__"
+
+        # This may not work perfectly, since it was designed for testcheck.py, use with care.
+        if testcase.output != e.messages and testcase.config.getoption("--update-data", False):
+            update_testcase_output(testcase, e.messages, incremental_step=1)
+
         # Verify that there was a compile error and that the error messages
         # are equivalent.
         assert_string_arrays_equal(
diff --git a/mypy/test/testsemanal.py b/mypy/test/testsemanal.py
index e11a25617fa48..a66280aea5e56 100644
--- a/mypy/test/testsemanal.py
+++ b/mypy/test/testsemanal.py
@@ -21,6 +21,7 @@
 
 # Semantic analyzer test cases: dump parse tree
 # Semantic analysis test case description files.
+from mypy.test.update_data import update_testcase_output
 from mypy.types import TypeStrVisitor
 
 semanal_files = find_test_files(
@@ -112,6 +113,11 @@ def test_semanal_error(testcase: DataDrivenTestCase) -> None:
         a = e.messages
     if testcase.normalize_output:
         a = normalize_error_messages(a)
+
+    # This may not work perfectly, since it was designed for testcheck.py, use with care.
+    if testcase.output != a and testcase.config.getoption("--update-data", False):
+        update_testcase_output(testcase, a, incremental_step=1)
+
     assert_string_arrays_equal(
         testcase.output, a, f"Invalid compiler output ({testcase.file}, line {testcase.line})"
     )
diff --git a/mypy/test/teststubtest.py b/mypy/test/teststubtest.py
index 2db149ce65c97..d6324dedec75f 100644
--- a/mypy/test/teststubtest.py
+++ b/mypy/test/teststubtest.py
@@ -3207,7 +3207,7 @@ def test_mypy_build(self) -> None:
         output = run_stubtest(stub="+", runtime="", options=[])
         assert output == (
             "error: not checking stubs due to failed mypy compile:\n{}.pyi:1: "
-            "error: Invalid syntax  [syntax]\n".format(TEST_MODULE_NAME)
+            "error: Expected an expression  [syntax]\n".format(TEST_MODULE_NAME)
         )
 
         output = run_stubtest(stub="def f(): ...\ndef f(): ...", runtime="", options=[])
diff --git a/test-data/unit/cmdline.test b/test-data/unit/cmdline.test
index 7066034b3e39c..41dd3bdb3da7d 100644
--- a/test-data/unit/cmdline.test
+++ b/test-data/unit/cmdline.test
@@ -760,7 +760,7 @@ some_file.py:11: error: Argument 1 to "some_interesting_method" of
 [file some_file.py]
 it_looks_like_we_started_typing_something_but_then. = did_not_notice(an_extra_dot)
 [out]
-some_file.py:1: error: Invalid syntax  [syntax]
+some_file.py:1: error: Expected an identifier  [syntax]
     ...ooks_like_we_started_typing_something_but_then. = did_not_notice(an_ex...
                                                         ^
 == Return code: 2
@@ -905,12 +905,10 @@ public static void main(String[] args)
 [file pkg/y.py]
 x: str = 0
 [out]
-pkg/x.py:1: error: Invalid syntax. Perhaps you forgot a comma?
-Found 1 error in 1 file (errors prevented further checking)
-== Return code: 2
-[out version>=3.10.3]
-pkg/x.py:1: error: Invalid syntax
-Found 1 error in 1 file (errors prevented further checking)
+pkg/x.py:1: error: Simple statements must be separated by newlines or semicolons
+pkg/x.py:1: error: Expected index or slice expression
+pkg/x.py:1: error: Expected `,`, found name
+Found 3 errors in 1 file (errors prevented further checking)
 == Return code: 2
 
 [case testCmdlinePackageAndFile]
diff --git a/test-data/unit/fine-grained-blockers.test b/test-data/unit/fine-grained-blockers.test
index 1bb1b3c44d2f4..24e26e145a36b 100644
--- a/test-data/unit/fine-grained-blockers.test
+++ b/test-data/unit/fine-grained-blockers.test
@@ -19,7 +19,7 @@ def f(x: int) -> None: pass
 def f() -> None: pass
 [out]
 ==
-a.py:1: error: Expected ':'
+a.py:1: error: Expected an expression
 ==
 main:2: error: Missing positional argument "x" in call to "f"
 ==
@@ -38,9 +38,9 @@ def f(x: int) -> None: pass
 def f() -> None: pass
 [out]
 ==
-a.py:1: error: Expected ':'  [syntax]
+a.py:1: error: Expected an expression  [syntax]
     def f(x: int) ->
-                   ^
+                    ^
 ==
 main:3: error: Missing positional argument "x" in call to "f"  [call-arg]
     a.f()
@@ -61,9 +61,9 @@ def f(x: int
 def f(x: int) -> None: pass
 [out]
 ==
-a.py:1: error: Expected ':'
+a.py:1: error: Expected an expression
 ==
-a.py:2: error: Expected ':'
+a.py:2: error: Expected `:`, found newline
 ==
 main:2: error: Missing positional argument "x" in call to "f"
 
@@ -101,7 +101,7 @@ def f() -> None: pass
 main:3: error: Too many arguments for "f"
 main:5: error: Too many arguments for "f"
 ==
-a.py:1: error: Expected ':'
+a.py:1: error: Expected `:`, found newline
 ==
 main:3: error: Too many arguments for "f"
 main:5: error: Too many arguments for "f"
@@ -122,12 +122,12 @@ class C:
     def f(self, x: int) -> None: pass
 [out]
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 main:5: error: Missing positional argument "x" in call to "f" of "C"
 [out version==3.10.0]
 ==
-a.py:1: error: Invalid syntax. Perhaps you forgot a comma?
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 main:5: error: Missing positional argument "x" in call to "f" of "C"
 
@@ -142,14 +142,14 @@ def f() -> None: pass
 main:1: error: Cannot find implementation or library stub for module named "a"
 main:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 main:2: error: Too many arguments for "f"
 [out version==3.10.0]
 main:1: error: Cannot find implementation or library stub for module named "a"
 main:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
 ==
-a.py:1: error: Invalid syntax. Perhaps you forgot a comma?
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 main:2: error: Too many arguments for "f"
 
@@ -177,7 +177,7 @@ a.f()
 def g() -> None: pass
 [out]
 ==
-b.py:1: error: Invalid syntax
+b.py:1: error: Expected `,`, found name
 ==
 
 [case testModifyTwoFilesOneWithBlockingError2]
@@ -204,7 +204,7 @@ def f() -> None: pass
 b.g()
 [out]
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Expected `,`, found name
 ==
 
 [case testBlockingErrorRemainsUnfixed]
@@ -223,16 +223,16 @@ import b
 b.f()
 [out]
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 a.py:2: error: Missing positional argument "x" in call to "f"
 [out version==3.10.0]
 ==
-a.py:1: error: Invalid syntax. Perhaps you forgot a comma?
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
-a.py:1: error: Invalid syntax. Perhaps you forgot a comma?
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 a.py:2: error: Missing positional argument "x" in call to "f"
 
@@ -272,9 +272,9 @@ def g() -> None: pass
 a.f(1)
 [out]
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Expected `,`, found name
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Expected `,`, found name
 ==
 a.py:3: error: Too many arguments for "g"
 b.py:3: error: Too many arguments for "f"
@@ -294,14 +294,14 @@ x x
 [delete a.py.3]
 [out]
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 main:1: error: Cannot find implementation or library stub for module named "a"
 main:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
 b.py:1: error: Cannot find implementation or library stub for module named "a"
 [out version==3.10.0]
 ==
-a.py:1: error: Invalid syntax. Perhaps you forgot a comma?
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 main:1: error: Cannot find implementation or library stub for module named "a"
 main:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
@@ -322,14 +322,14 @@ x x
 [delete a.py.3]
 [out]
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 b.py:1: error: Cannot find implementation or library stub for module named "a"
 b.py:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
 main:1: error: Cannot find implementation or library stub for module named "a"
 [out version==3.10.0]
 ==
-a.py:1: error: Invalid syntax. Perhaps you forgot a comma?
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 b.py:1: error: Cannot find implementation or library stub for module named "a"
 b.py:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
@@ -351,17 +351,17 @@ a.f()
 [builtins fixtures/module.pyi]
 [out]
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 b.py:2: error: Module has no attribute "f"
 b.py:3: error: "int" not callable
 [out version==3.10.0]
 ==
-a.py:1: error: Invalid syntax. Perhaps you forgot a comma?
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
-a.py:1: error: Invalid syntax. Perhaps you forgot a comma?
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 b.py:2: error: Module has no attribute "f"
 b.py:3: error: "int" not callable
@@ -377,12 +377,12 @@ import blocker
 def f() -> None: pass
 [out]
 ==
-<ROOT>/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax
+<ROOT>/test-data/unit/lib-stub/blocker.pyi:2: error: Simple statements must be separated by newlines or semicolons
 ==
 a.py:1: error: "int" not callable
 [out version==3.10.0]
 ==
-<ROOT>/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax. Perhaps you forgot a comma?
+<ROOT>/test-data/unit/lib-stub/blocker.pyi:2: error: Simple statements must be separated by newlines or semicolons
 ==
 a.py:1: error: "int" not callable
 
@@ -454,16 +454,16 @@ import sys
 [builtins fixtures/tuple.pyi]
 [out]
 ==
-a.py:1: error: Invalid syntax
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
-<ROOT>/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax
+<ROOT>/test-data/unit/lib-stub/blocker.pyi:2: error: Simple statements must be separated by newlines or semicolons
 ==
 a.py:2: error: "int" not callable
 [out version==3.10.0]
 ==
-a.py:1: error: Invalid syntax. Perhaps you forgot a comma?
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
-<ROOT>/test-data/unit/lib-stub/blocker.pyi:2: error: Invalid syntax. Perhaps you forgot a comma?
+<ROOT>/test-data/unit/lib-stub/blocker.pyi:2: error: Simple statements must be separated by newlines or semicolons
 ==
 a.py:2: error: "int" not callable
 
@@ -480,12 +480,12 @@ x = 1
 def f() -> int:
     return 0
 [out]
-a.py:1: error: Invalid syntax
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 b.py:2: error: Incompatible return value type (got "str", expected "int")
 ==
 [out version==3.10.0]
-a.py:1: error: Invalid syntax. Perhaps you forgot a comma?
+a.py:1: error: Simple statements must be separated by newlines or semicolons
 ==
 b.py:2: error: Incompatible return value type (got "str", expected "int")
 ==
@@ -532,6 +532,6 @@ a.f(1)
 [file a.py.2]
 def f(x: str) -> None: ...
 [out]
-a.py: error: Cannot decode file: 'ascii' codec can't decode byte 0xc3 in position 16: ordinal not in range(128)
+main:3: error: "object" has no attribute "f"
 ==
 main:3: error: Argument 1 to "f" has incompatible type "int"; expected "str"
diff --git a/test-data/unit/fine-grained-suggest.test b/test-data/unit/fine-grained-suggest.test
index 499a0b4a76fd7..5f83e3f35d3c8 100644
--- a/test-data/unit/fine-grained-suggest.test
+++ b/test-data/unit/fine-grained-suggest.test
@@ -1117,10 +1117,10 @@ def foo():
 
 (
 [out]
-foo.py:4: error: '(' was never closed
+foo.py:4: error: Unexpected EOF while parsing
 Command 'suggest' is only valid after a 'check' command (that produces no parse errors)
 ==
-foo.py:4: error: '(' was never closed
+foo.py:4: error: Unexpected EOF while parsing
 -- )
 
 [case testSuggestRefine]
diff --git a/test-data/unit/outputjson.test b/test-data/unit/outputjson.test
index ec716d97b8f1e..1473e4bc27755 100644
--- a/test-data/unit/outputjson.test
+++ b/test-data/unit/outputjson.test
@@ -56,7 +56,7 @@ foo(1)
 # flags: --output=json
 klass foo
 [out]
-{"file": "main", "line": 2, "column": 7, "end_line": 2, "end_column": 8, "message": "Invalid syntax", "hint": null, "code": "syntax", "severity": "error"}
+{"file": "main", "line": 2, "column": 7, "end_line": 2, "end_column": 8, "message": "Simple statements must be separated by newlines or semicolons", "hint": null, "code": "syntax", "severity": "error"}
 !!! Mypy crashed !!!
 
 [case testOutputJsonSyntaxErrorParallel]
diff --git a/test-data/unit/parse-errors.test b/test-data/unit/parse-errors.test
index 23e24ea034e83..5625b8f4f383c 100644
--- a/test-data/unit/parse-errors.test
+++ b/test-data/unit/parse-errors.test
@@ -18,14 +18,16 @@ file:1: error: Expected ':'
 1
  2
 [out]
-file:2: error: Unexpected indent
+file:2: error: Unexpected indentation
+file:2: error: Expected a statement
 
 [case testInconsistentIndent]
 if x:
   1
    1
 [out]
-file:3: error: Unexpected indent
+file:3: error: Unexpected indentation
+file:3: error: Expected a statement
 
 [case testInconsistentIndent2]
 if x:
@@ -33,81 +35,85 @@ if x:
   1
 [out]
 file:3: error: Unindent does not match any outer indentation level
+file:3: error: Expected dedent, found end of file
 
 [case testInvalidBinaryOp]
 1>
 a*
 a+1*
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected an expression
+file:2: error: Expected an expression
+file:3: error: Expected an expression
 
 [case testDoubleStar]
 **a
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected an expression
 
 [case testMissingSuperClass]
 class A(:
   pass
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected an expression or a ')'
+file:1: error: Expected `)`, found newline
 
 [case testUnexpectedEof]
 if 1:
 [out]
-file:1: error: Expected an indented block after 'if' statement on line 1
+file:1: error: Expected an indented block after `if` statement
 
 [case testInvalidKeywordArguments1]
 f(x=y, z)
 [out]
-file:1: error: Positional argument follows keyword argument
+file:1: error: Positional argument cannot follow keyword argument
 
 [case testInvalidKeywordArguments2]
 f(**x, y)
 [out]
-file:1: error: Positional argument follows keyword argument unpacking
+file:1: error: Positional argument cannot follow keyword argument unpacking
 
 [case testInvalidBareAsteriskAndVarArgs2]
 def f(*x: A, *) -> None: pass
 [out]
-file:1: error: Invalid syntax
+file:1: error: Keyword-only parameter separator not allowed after '*' parameter
 
 [case testInvalidBareAsteriskAndVarArgs3]
 def f(*, *x: A) -> None: pass
 [out]
-file:1: error: Invalid syntax
+file:1: error: Only one '*' parameter allowed
 
 [case testInvalidBareAsteriskAndVarArgs4]
 def f(*, **x: A) -> None: pass
 [out]
-file:1: error: Named arguments must follow bare *
+file:1: error: Expected one or more keyword parameter after `*` separator
 
 [case testInvalidBareAsterisk1]
 def f(*) -> None: pass
 [out]
-file:1: error: Named arguments must follow bare *
+file:1: error: Expected one or more keyword parameter after `*` separator
 
 [case testInvalidBareAsterisk2]
 def f(x, *) -> None: pass
 [out]
-file:1: error: Named arguments must follow bare *
+file:1: error: Expected one or more keyword parameter after `*` separator
 
 [case testInvalidFuncDefArgs1]
 def f(x = y, x): pass
 [out]
-file:1: error: Non-default argument follows default argument
+file:1: error: Parameter without a default cannot follow a parameter with a default
 
 [case testInvalidFuncDefArgs3]
 def f(**x, y):
    pass
 [out]
-file:1: error: Invalid syntax
+file:1: error: Parameter cannot follow var-keyword parameter
 
 [case testInvalidFuncDefArgs4]
 def f(**x, y=x):
     pass
 [out]
-file:1: error: Invalid syntax
+file:1: error: Parameter cannot follow var-keyword parameter
 
 [case testInvalidTypeComment]
 0
@@ -154,7 +160,7 @@ file:2: error: Syntax error in type comment "A B"
 [case testMissingBracket]
 def foo(
 [out]
-file:1: error: '(' was never closed
+file:1: error: Unexpected EOF while parsing
 
 [case testInvalidSignatureInComment1]
 def f(): # type: x
@@ -203,7 +209,7 @@ file:1: error: Syntax error in type comment "(x) -"
 def f(): # type: (x) ->
   pass
 [out]
-file:1: error: Syntax error in type comment "(x) ->"
+file:1: error: Type signature has too many parameters
 
 [case testInvalidSignatureInComment9]
 def f(): # type: (x) -> .
@@ -281,96 +287,103 @@ file:3: error: Inconsistent use of "**" in function signature
 [case testPrintStatementInPython3]
 print 1
 [out]
-file:1: error: Missing parentheses in call to 'print'. Did you mean print(...)?
+file:1: error: Simple statements must be separated by newlines or semicolons
 
 [case testInvalidConditionInConditionalExpression]
 1 if 2, 3 else 4
 [out]
-file:1: error: Expected 'else' after 'if' expression
+file:1: error: Expected `else`, found `,`
+file:1: error: Expected a statement
 
 [case testInvalidConditionInConditionalExpression2]
 1 if x for y in z else 4
 [out]
-file:1: error: Expected 'else' after 'if' expression
+file:1: error: Expected `else`, found `for`
+file:1: error: Simple statements must be separated by newlines or semicolons
+file:1: error: Expected a statement
 
 [case testInvalidConditionInConditionalExpression3]
 1 if x else for y in z
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected an identifier, but found a keyword `for` that cannot be used here
+file:1: error: Simple statements must be separated by newlines or semicolons
 
 [case testYieldFromNotRightParameter]
 def f():
     yield from
 [out]
-file:2: error: Invalid syntax
+file:2: error: Expected an expression
 
 [case testYieldFromAfterReturn]
 def f():
     return yield from h()
 [out]
-file:2: error: Invalid syntax
+file:2: error: Yield expression cannot be used here
 
 [case testImportDotModule]
 import .x
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected an import name
 
 [case testImportDot]
 import .
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected an import name
+file:1: error: Expected one or more symbol names after import
 
 [case testInvalidFunctionName]
 def while(): pass
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected an identifier, but found a keyword `while` that cannot be used here
 
 [case testInvalidEllipsis1]
 ...0
 ..._
 ...a
 [out]
-file:1: error: Invalid syntax
+file:1: error: Simple statements must be separated by newlines or semicolons
+file:2: error: Simple statements must be separated by newlines or semicolons
+file:3: error: Simple statements must be separated by newlines or semicolons
 
 [case testBlockStatementInSingleLineIf]
 if 1: if 2: pass
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected a simple statement
 
 [case testBlockStatementInSingleLineIf2]
 if 1: while 2: pass
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected a simple statement
 
 [case testBlockStatementInSingleLineIf3]
 if 1: for x in y: pass
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected a simple statement
 
 [case testUnexpectedEllipsis]
 a = a...
 [out]
-file:1: error: Invalid syntax
+file:1: error: Simple statements must be separated by newlines or semicolons
 
 [case testParseErrorBeforeUnicodeLiteral]
 x u'y'
 [out]
-file:1: error: Invalid syntax
+file:1: error: Simple statements must be separated by newlines or semicolons
 
 [case testParseErrorInExtendedSlicing]
 x[:,
 [out]
-file:1: error: '[' was never closed
+file:1: error: Unexpected EOF while parsing
 
 [case testParseErrorInExtendedSlicing2]
 x[:,::
 [out]
-file:1: error: '[' was never closed
+file:1: error: Unexpected EOF while parsing
 
 [case testParseErrorInExtendedSlicing3]
 x[:,:
 [out]
-file:1: error: '[' was never closed
+file:1: error: Unexpected EOF while parsing
 
 [case testInvalidEncoding]
 # foo
@@ -407,17 +420,19 @@ file:0: error: Unknown encoding: uft8
 2L
 0x2L
 [out]
-file:1: error: Invalid decimal literal
+file:1: error: Simple statements must be separated by newlines or semicolons
+file:2: error: Simple statements must be separated by newlines or semicolons
 
 [case testPython2LegacyInequalityInPython3]
 1 <> 2
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected an expression
 
 [case testLambdaInListComprehensionInPython3]
 ([ 0 for x in 1, 2 if 3 ])
 [out]
-file:1: error: Invalid syntax
+file:1: error: Expected `]`, found `,`
+file:1: error: Expected `else`, found `]`
 
 [case testTupleArgListInPython3]
 def f(x, (y, z)): pass
@@ -427,12 +442,15 @@ file:1: error: Invalid syntax
 [case testBackquoteInPython3]
 `1 + 2`
 [out]
-file:1: error: Invalid syntax
+file:1: error: Got unexpected token `
+file:1: error: Expected a statement
 
 [case testSmartQuotes]
 foo = ‘bar’
 [out]
-file:1: error: Invalid character '‘' (U+2018)
+file:1: error: Got unexpected token ‘
+file:1: error: Got unexpected token ’
+file:1: error: Expected a statement
 
 [case testExceptCommaInPython3]
 try:
diff --git a/test-data/unit/parse.test b/test-data/unit/parse.test
index 1e43600e56898..22dce419f7d69 100644
--- a/test-data/unit/parse.test
+++ b/test-data/unit/parse.test
@@ -948,20 +948,18 @@ MypyFile:1(
 [case testNotAsBinaryOp]
 x not y
 [out]
-main:1: error: Invalid syntax
-[out version==3.10.0]
-main:1: error: Invalid syntax. Perhaps you forgot a comma?
+main:1: error: Simple statements must be separated by newlines or semicolons
 
 [case testNotIs]
-x not is y # E: Invalid syntax
+x not is y
 [out]
+main:1: error: Simple statements must be separated by newlines or semicolons
+main:1: error: Expected an identifier, but found a keyword `is` that cannot be used here
 
 [case testBinaryNegAsBinaryOp]
 1 ~ 2
 [out]
-main:1: error: Invalid syntax
-[out version==3.10.0]
-main:1: error: Invalid syntax. Perhaps you forgot a comma?
+main:1: error: Simple statements must be separated by newlines or semicolons
 
 [case testSliceInList]
 x = [1, 2][1:2]
diff --git a/test-data/unit/semanal-errors.test b/test-data/unit/semanal-errors.test
index 7e1f737c61b21..62669ed3f1fc7 100644
--- a/test-data/unit/semanal-errors.test
+++ b/test-data/unit/semanal-errors.test
@@ -398,70 +398,70 @@ main:2: error: "yield" outside function
 [case testInvalidLvalues1]
 1 = 1
 [out]
-main:1: error: Cannot assign to literal here. Maybe you meant '==' instead of '='?
+main:1: error: Invalid assignment target
 
 [case testInvalidLvalues2]
 (1) = 1
 [out]
-main:1: error: Cannot assign to literal here. Maybe you meant '==' instead of '='?
+main:1: error: Invalid assignment target
 
 [case testInvalidLvalues3]
 (1, 1) = 1
 [out]
-main:1: error: Cannot assign to literal
+main:1: error: Invalid assignment target
 
 [case testInvalidLvalues4]
 [1, 1] = 1
 [out]
-main:1: error: Cannot assign to literal
+main:1: error: Invalid assignment target
 
 [case testInvalidLvalues6]
 x = y = z = 1  # ok
 x, (y, 1) = 1
 [out]
-main:2: error: Cannot assign to literal
+main:2: error: Invalid assignment target
 
 [case testInvalidLvalues7]
 x, [y, 1] = 1
 [out]
-main:1: error: Cannot assign to literal
+main:1: error: Invalid assignment target
 
 [case testInvalidLvalues8]
 x, [y, [z, 1]] = 1
 [out]
-main:1: error: Cannot assign to literal
+main:1: error: Invalid assignment target
 
 [case testInvalidLvalues9]
 x, (y) = 1 # ok
 x, (y, (z, z)) = 1 # ok
 x, (y, (z, 1)) = 1
 [out]
-main:3: error: Cannot assign to literal
+main:3: error: Invalid assignment target
 
 [case testInvalidLvalues10]
 x + x = 1
 [out]
-main:1: error: Cannot assign to expression here. Maybe you meant '==' instead of '='?
+main:1: error: Invalid assignment target
 
 [case testInvalidLvalues11]
 -x = 1
 [out]
-main:1: error: Cannot assign to expression here. Maybe you meant '==' instead of '='?
+main:1: error: Invalid assignment target
 
 [case testInvalidLvalues12]
 1.1 = 1
 [out]
-main:1: error: Cannot assign to literal here. Maybe you meant '==' instead of '='?
+main:1: error: Invalid assignment target
 
 [case testInvalidLvalues13]
 'x' = 1
 [out]
-main:1: error: Cannot assign to literal here. Maybe you meant '==' instead of '='?
+main:1: error: Invalid assignment target
 
 [case testInvalidLvalues14]
 x() = 1
 [out]
-main:1: error: Cannot assign to function call here. Maybe you meant '==' instead of '='?
+main:1: error: Invalid assignment target
 
 [case testTwoStarExpressions]
 a, *b, *c = 1
@@ -515,13 +515,13 @@ main:2: error: can't use starred expression here
 x = 1
 del x(1)
 [out]
-main:2: error: Cannot delete function call
+main:2: error: Invalid delete target
 
 [case testInvalidDel2]
 x = 1
 del x + 1
 [out]
-main:2: error: Cannot delete expression
+main:2: error: Invalid delete target
 
 [case testInvalidDel3]
 del z     # E: Name "z" is not defined
@@ -902,7 +902,7 @@ import typing
 def f(): pass
 f() = 1 # type: int
 [out]
-main:3: error: Cannot assign to function call here. Maybe you meant '==' instead of '='?
+main:3: error: Invalid assignment target
 
 [case testIndexedAssignmentWithTypeDeclaration]
 import typing
@@ -978,7 +978,7 @@ x, y = 1, 2 # type: int # E: Tuple type expected for multiple variables
 a = 1
 a() = None # type: int
 [out]
-main:2: error: Cannot assign to function call here. Maybe you meant '==' instead of '='?
+main:2: error: Invalid assignment target
 
 [case testInvalidLvalueWithExplicitType2]
 a = 1
@@ -1306,7 +1306,7 @@ main:2: note: Did you forget to import it from "typing"? (Suggestion: "from typi
 def f(): pass
 with f() as 1: pass
 [out]
-main:2: error: Cannot assign to literal
+main:2: error: Invalid assignment target
 
 [case testInvalidTypeAnnotation]
 import typing
@@ -1320,7 +1320,7 @@ import typing
 def f() -> None:
     f() = 1  # type: int
 [out]
-main:3: error: Cannot assign to function call here. Maybe you meant '==' instead of '='?
+main:3: error: Invalid assignment target
 
 [case testInvalidReferenceToAttributeOfOuterClass]
 class A:
diff --git a/test-data/unit/semanal-statements.test b/test-data/unit/semanal-statements.test
index 13999c4ed02d2..4f377236d74db 100644
--- a/test-data/unit/semanal-statements.test
+++ b/test-data/unit/semanal-statements.test
@@ -557,7 +557,7 @@ MypyFile:1(
 def f(x, y) -> None:
     del x, y + 1
 [out]
-main:2: error: Cannot delete expression
+main:2: error: Invalid delete target
 
 [case testTry]
 class c: pass