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.
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.