A modal is a type of auxiliary (helping) verb that is used to express: ability, possibility, permission, request, obligation, suggestion, among others.
Modal verbs are always followed by the base form of any verb.
Pattern for questions:
[modal verb] + [subject] + [main verb]
Could you open the window?

Modals of polite requests:
Would
Could
Will
Can

How should polite requests be responded?

There are many ways in which we can respond politely to a request...

Take me to the university.

Return these books to the library for me.

Help me to clean the house before my parents get home

Bring me a cup of coffee with sweet bread.

Buy the pupusas for me.

Let me use your headphones.