Grammatical fixes (#21644)

examples/custom-server-express/README.md

@@ -1,10 +1,10 @@
 # Custom Express Server example
 
-Most of the times the default Next server will be enough but sometimes you want to run your own server to customize routes or other kind of the app behavior. Next provides a [Custom server and routing](https://github.com/vercel/next.js#custom-server-and-routing) so you can customize as much as you want.
+Most of the time the default Next.js server will be enough but there are times you'll want to run your own server to customize routes or other kinds of app behavior. Next.js provides [Custom server and routing](https://github.com/vercel/next.js#custom-server-and-routing) options, so you can customize as much as you want.
 
-Because the Next.js server is just a node.js module you can combine it with any other part of the node.js ecosystem. in this case we are using express to build a custom router on top of Next.
+Because the Next.js server is just a node.js module you can combine it with any other part of the node.js ecosystem. In this case we are using express to build a custom router on top of Next.
 
-The example shows a server that serves the component living in `pages/a.js` when the route `/b` is requested and `pages/b.js` when the route `/a` is accessed. This is obviously a non-standard routing strategy. You can see how this custom routing is being made inside `server.js`.
+This example demonstrates a server that serves the component living in `pages/a.js` when the route `/b` is requested and `pages/b.js` when the route `/a` is accessed. This is obviously a non-standard routing strategy. You can see how this custom routing is being made inside `server.js`.
 
 ## How to use