Learn English – when to use “to” and when not

infinitivesmodal-verbsto-infinitive

I have a question about the "to" usage in the English. So, instead of "Can someone to help me?" we are saying "Can someone help me?" but I never understood why we are doing it in such way.

Also the same with this:

Can you to play football with me? – incorrect
Can you play football with me? – correct

But why? Could someone explain me this please?

Best Answer

Modal verbs are followed by the plain form of verb. So the verb cannot be preceded by 'to', or be attached with -ing, and -ed suffix.

This is rule is not applied to the entire sentence. The verb that should be the plain form is the verb that's 'helped' by the modal verb. You can identify this verb by paraphrasing it with a wh-cleft construction. For example,

He can't {say/to say} he {like/to like/likes} me.

Paraphrase it to...

What he can do is say he likes me.

The verb that follows the is is the verb that should be in the plain form.