Update part8e.md

corrected grammar error

Author: eedrxs

src/content/8/en/part8e.md

@@ -535,7 +535,7 @@ start()
 
 When queries and mutations are used, GraphQL uses the HTTP protocol in the communication. In case of subscriptions, the communication between client and server happens with [WebSockets](https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API).
 
-The above code registers a WebSocketServer object to listen the WebSocket connections, besides the usual HTTP connections that the server listens to. The second part of the definition registers a function that closes the WebSocket connection on server shutdown.
+The above code registers a WebSocketServer object to listen to WebSocket connections, besides the usual HTTP connections that the server listens to. The second part of the definition registers a function that closes the WebSocket connection on server shutdown.
 If you're interested in more details about configurations, Apollo's [documentation](https://www.apollographql.com/docs/apollo-server/data/subscriptions) explains in relative detail what each line of code does.
 
 WebSockets are a perfect match for communication in the case of GraphQL subscriptions since when WebSockets are used, also the server can initiate the communication.