Issue #25523: Backported a-to-an corrections.
diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index 5e3bd1c..ca91cd7 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -568,7 +568,7 @@
.. versionadded:: 2.7
Unittest supports skipping individual test methods and even whole classes of
-tests. In addition, it supports marking a test as a "expected failure," a test
+tests. In addition, it supports marking a test as an "expected failure," a test
that is broken and will fail, but shouldn't be counted as a failure on a
:class:`TestResult`.