diff --git a/guide/english/progressive-web-apps/service-workers/index.md b/guide/english/progressive-web-apps/service-workers/index.md
index 4095877419..f98ed6a2a6 100644
--- a/guide/english/progressive-web-apps/service-workers/index.md
+++ b/guide/english/progressive-web-apps/service-workers/index.md
@@ -3,7 +3,7 @@ title: Service Workers
 ---
 ## Service Workers
 
-Service Worker is a script that works on browser background without user interaction independently. Also, It resembles a proxy that works on the user side. With this script, you can track network traffic of the page, manage push notifications and develop “offline first” web applications with Cache API.
+A Service Worker is a script that works in the browser background without user interaction independently. Also, It resembles a proxy that works on the user side. With this script, you can track network traffic of the page, manage push notifications and develop “offline first” web applications with Cache API.
 
 ### What can we do with Service Worker?