diff --git a/source/tutorial/optimize-query-performance-with-indexes-and-projections.txt b/source/tutorial/optimize-query-performance-with-indexes-and-projections.txt
index e44144e4e3d..80a7d7e2f55 100644
--- a/source/tutorial/optimize-query-performance-with-indexes-and-projections.txt
+++ b/source/tutorial/optimize-query-performance-with-indexes-and-projections.txt
@@ -10,8 +10,8 @@ Create Indexes to Support Queries
 For commonly issued queries, create :doc:`indexes </indexes>`. If a
 query searches multiple fields, create a :ref:`compound index
 <index-type-compound>`. Scanning an index is much faster than scanning a
-collection. The indexes structures are smaller than the documents
-reference, and store references in order.
+collection. The index structures are smaller than the documents they
+reference, and these references are stored in order.
 
 .. example:: If you have a ``posts`` collection containing blog posts,
    and if you regularly issue a query that sorts on the ``author_name``