doc: fix typo
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index f8b1025..67f94ac 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -962,7 +962,7 @@
 .. function:: pipe()
 
    Create a pipe.  Return a pair of file descriptors ``(r, w)`` usable for
-   reading and writing, respectively. The new file descriptor are
+   reading and writing, respectively. The new file descriptor is
    :ref:`non-inheritable <fd_inheritance>`.
 
    Availability: Unix, Windows.