Fix a grammatical problem and reword for clarity. (#4257)

bpo-31936

Doc/reference/import.rst

@@ -28,11 +28,10 @@ such as the importing of parent packages, and the updating of various caches
 (including :data:`sys.modules`), only the :keyword:`import` statement performs
 a name binding operation.
 
-When calling :func:`__import__` as part of an import statement, the
-standard builtin :func:`__import__` is called. Other mechanisms for
-invoking the import system (such as :func:`importlib.import_module`) may
-choose to subvert :func:`__import__` and use its own solution to
-implement import semantics.
+When an :keyword:`import` statement is executed, the standard builtin
+:func:`__import__` function is called. Other mechanisms for invoking the
+import system (such as :func:`importlib.import_module`) may choose to bypass
+:func:`__import__` and use their own solutions to implement import semantics.
 
 When a module is first imported, Python searches for the module and if found,
 it creates a module object [#fnmo]_, initializing it.  If the named module