diff --git a/book/chapter-01-run-and-talk.md b/book/chapter-01-run-and-talk.md
index 58548f49..f83a0806 100644
--- a/book/chapter-01-run-and-talk.md
+++ b/book/chapter-01-run-and-talk.md
@@ -11,7 +11,7 @@
 gbapp and gblib are responsible for GeneralBots services in a Back-end development environment.
 
 2- The .gbui extension is assigned to the GeneralBots front-end development environment. 
-Angular, Riot, React and HTML are responsible for the dynamic functioning of GeneralBots services
+Angular, Riot, React and HTML are responsible for the dynamic functioning of GeneralBots services.
 
 ### The Bot Factory