Update ref-10-glossary.md

docs/ref-10-glossary.md

@@ -133,7 +133,7 @@ var componentB = ReactDOM.render(<MyComponent />, document.getElementById('examp
 componentA === componentB; // true
 ```
 
-This is why you shouldn't construct your own instance. Instead, `ReactElement` is a virtual `ReactComponent` before it gets constructed. An old and new `ReactElement` can be compared to see if a new `ReactComponent` instance is created or if the existing one is reused.
+This is why you shouldn't construct your own instance. Instead, `ReactElement` is a virtual `ReactComponent` before it gets constructed. An old and new `ReactElement` can be compared to see if a new `ReactComponent` instance should be created or if the existing one should be reused.
 
 The `render` method of a `ReactComponent` is expected to return another `ReactElement`. This allows these components to be composed. Ultimately the render resolves into `ReactElement` with a `string` tag which instantiates a DOM `Element` instance and inserts it into the document.