Usage = noun that means that language is being used in this country.
Use can mean the same the thing but it also has another meaning.
For example:
The usage of English is growing in the world.
The use of English is growing in the world. (Means the same but less common and I believe is also not grammatically correct for writing but in speaking it's fine.)
Extra meaning for use
<ul><li>What's the
use of learning a language? (Means why do we need to learn a language?) </li></ul>
Hope that helps.