diff --git a/README.md b/README.md
index 689e614..37b39b8 100644
--- a/README.md
+++ b/README.md
@@ -6,10 +6,9 @@ Maintained by the [MDN team at Mozilla](https://wiki.mozilla.org/MDN).
 
 WebExtensions are a way to write browser extensions: that is, programs
 installed inside a web browser that modify the behaviour of the browser or
-of web pages loaded by the browser.
-
-WebExtensions are built on a set of cross-browser APIs: WebExtensions written
-for Google Chrome or Opera will in most cases run in Firefox or Edge too.
+of web pages loaded by the browser. They are built on a set of
+cross-browser APIs, so WebExtensions written for Google Chrome or Opera will
+in most cases run in Firefox or Edge too.
 
 The "webextensions-examples" repository is a collection of simple but complete
 and installable WebExtensions. You can use the examples to see how to use the