Fix sentence

Author: micpob

src/content/9/en/part9c.md

@@ -711,7 +711,7 @@ One thing in our application is a cause for concern. In *getNonSensitiveEntries*
 
 This happens because [TypeScript only checks](http://www.typescriptlang.org/docs/handbook/type-compatibility.html) whether we have all of the required fields or not, but excess fields are not prohibited. In our case, this means that it is <i>not prohibited</i> to return an object of type *DiaryEntry[]*, but if we were to try to access the *comment* field, it would not be possible because we would be accessing a field that TypeScript is unaware of even though it exists.
 
-Unfortunately, this can lead to unwanted behavior if you are not aware of what you are doing; the situation is valid as far as TypeScript is concerned, but you are most likely allowing use that is not wanted.
+Unfortunately, this can lead to unwanted behavior if you are not aware of what you are doing; the situation is valid as far as TypeScript is concerned, but you are most likely allowing a use that is not wanted.
 If we were now to return all of the diary entries from the *getNonSensitiveEntries* function to the frontend, we would be <i>leaking the unwanted fields to the requesting browser</i> - even though our types seem to imply otherwise!
 
 Because TypeScript doesn't modify the actual data but only its type, we need to exclude the fields ourselves: