small grammar fix.
diff --git a/Doc/library/select.rst b/Doc/library/select.rst
index f5f90bb..4fae87e 100644
--- a/Doc/library/select.rst
+++ b/Doc/library/select.rst
@@ -313,7 +313,7 @@
 
 .. method:: epoll.modify(fd, eventmask)
 
-   Modify a register file descriptor.
+   Modify a registered file descriptor.
 
 
 .. method:: epoll.unregister(fd)