diff --git a/chapter03.tex b/chapter03.tex
index b5a5f43..a154367 100644
--- a/chapter03.tex
+++ b/chapter03.tex
@@ -15,7 +15,7 @@ If the array contains two equal elements,
 they will be next to each other after sorting,
 so it is easy to find them.
 Also, the problem ''what is the most frequent element
-in the array?'' can be solved similarly.
+in an array?'' can be solved similarly.
 
 There are many algorithms for sorting, and they are
 also good examples of how to apply