typo

1 files changed, 1 insertions, 1 deletions

diff --git a/README.md b/README.md
index 313c1d7..604b607 100644
--- a/README.md
+++ b/README.md
@@ -73,7 +73,7 @@ If you have never heard of generators before, let me offer a
 definition.
 
 A generator is an object that can produce a series of values, one
-value at a time.  Generators sometimes convenient when you want to
+value at a time.  Generators are sometimes convenient when you want to
 deal with series that are too long to fit into memory. They also help
 when you want to generate sequential data using functions.