fix grammar

diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 3d7e0be0348f63f4a40660e5cedf7310782683e1..01fde3efba1a69d1a8af38758df9efcfa06b3bcf 100644 (file)
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -359,7 +359,7 @@ Sequences
       slicing notations can be used as the target of assignment and :keyword:`del`
       (delete) statements.
 
-      There is currently a single intrinsic mutable sequence type:
+      There are currently two intrinsic mutable sequence types:
 
       Lists
          .. index:: object: list