Grammar nit.  SF bug #757822
diff --git a/Doc/lib/libweakref.tex b/Doc/lib/libweakref.tex
index 9e07b00..664b76d 100644
--- a/Doc/lib/libweakref.tex
+++ b/Doc/lib/libweakref.tex
@@ -19,7 +19,7 @@
 
 XXX --- need to say more here!
 
-Not all objects can be weakly referenced; those objects which do
+Not all objects can be weakly referenced; those objects which can
 include class instances, functions written in Python (but not in C),
 and methods (both bound and unbound).  Extension types can easily
 be made to support weak references; see section \ref{weakref-extension},