This article is additional to the main page dedicated to Modal Verbs.
There are several modal verbs that are used when we ask for permission or give permission. These verbs are: can, could, may. Let's find the differences between them.
May
When we want to ask for permission or to give permission in an extremely polite and formal way, we use the modal 'may'.
May I open the window?
You may take your documents.
Could
The modal verb 'could' is less formal, but still a very polite way to ask for permission or to give permission.
Could I take this chair?
You could take this chair, please, it's free.
Can
The modal verb 'can' is an informal way to ask for permission or to give permission.
Can you show me the map?
You can take my headphones if you want.