More wordsmithing

test_cases/README.md

@@ -6,16 +6,16 @@ pass a type checker without error.
 
 The internal structure of this directory should mimic typeshed as a whole.
 However, unlike the rest of typeshed, this directory largely contains `.py`
-files, because the purpose of this folder is to test the implications of
-typeshed changes for end-users. For example, the stub for `builtins.pow` is
+files. This is because the purpose of this folder is to test the implications
+of typeshed changes for end users. For example, the stub for `builtins.pow` is
 found in `stdlib/builtins.pyi`, and the regression tests for `pow` are found in
 `test_cases/stdlib/test_builtins.py`.
 
 100% test coverage for typeshed is neither necessary nor desirable, as it would
-lead to unnecessary code duplication, and we have multiple other mechanisms for
-spotting errors in the stubs. As such, this directory should only contain tests
-for functions and classes which are known to have caused problems in the past,
-and are difficult to get right.
+lead to unnecessary code duplication. Moreover, typeshed has multiple other
+mechanisms for spotting errors in the stubs. As such, this directory should
+only contain tests for functions and classes which are known to have caused
+problems in the past, where the stubs are difficult to get right.
 
 Note that, unlike elsewhere in typeshed, the test cases in this directory
 cannot always use modern syntax for type hints. For example, PEP 604 syntax