Change docs

Doc/library/threading.rst

@@ -366,9 +366,9 @@ since it is impossible to detect the termination of alien threads.
    .. note::
 
       Threads are non-daemon by default, meaning they block the program from
-      exiting until they complete. By setting *daemon* to ``True``, thread becomes
+      exiting until they complete. By setting *daemon* to ``True``, threads become
       daemon and will be forcibly terminated when the main program exits. Use
-      an explicit call to ``.join()`` on the daemon thread, which will block
+      an explicit call to ``.join()`` on a daemon thread to block
       the main program until the thread completes.
 
    .. versionchanged:: 3.3