How to use 'APPLY'

 REPLY- contexts/ usages

1.To request something, usually officially, especially in writing or by sending in a form:

Please apply in writing to the address below.

We've applied to a charitable organization for a grant for the project.

[ + to infinitive ] Mandy applied to join the police.

2.To request something, usually officially, esp. by writing or by sending in a form:

to apply for a job/loan

She applied for admission to law school.

3.(especially of rules or laws) to have a connection or be important:

That part of the form is for UK citizens - it doesn't apply to you.

4.To make use of something or use it for a practical purpose:

He wants a job in which he can apply his foreign languages.

The court heard how the driver had failed to apply his brakes in time.

If you apply pressure to a cut it's meant to stop the bleeding.

5. a)To spread or rub a substance such as cream or paint on a surface:

Apply the cream liberally to exposed areas every three hours and after swimming.

b)If you apply something to a surface, you put it on or rub it into the surface. 

Applying the dye can be messy, particularly on long hair.

Apply the cream evenly over the skin.

6.If you apply yourself to something, you work hard at it, directing your abilities and efforts in a determined way so that you succeed:

You can solve any problem if you apply yourself.

Source 

Cambridge dictionary