DOCS-1026: correcting typo

Author: Sam Kleinman

source/reference/limits.txt

@@ -79,9 +79,9 @@ Indexes
    index name is the concatenation of the field names and index
    directions.
 
-   You can explicitly specific a name to the
-   :method:`~db.collection.ensureIndex()`
-   helper if the default index name is too long.
+   You can explicitly specify an index name to the
+   :method:`~db.collection.ensureIndex()` helper if the default index
+   name is too long.
 
 .. _limit-sharding-unique-indexes:
 .. limit:: Unique Indexes in Sharded Collections