[Grammar] Who plays tennis with you?

[FreeZiebel]

What grammar rules explain the change in verb tense in these two ways of forming questions?

Who plays tennis with you?
Who do you play tennis with?

Who likes the boy?
Who does the boy like?

Thanks.

[Edit] I guess it's to do with subject questions and object questions, but is there some more explicit grammar rule to explain this, or is it just the way we form subject and object questions?

Not a professional teacher...

 

[Barb_D]

Once you use a form of the verb "to do" then the
main verb goes to its "bare" form, e.g., like or play. That​ is, the infinitive without the "to."

 

[5jj]

See the answer here.

 

[FreeZiebel]

Thanks for the replies.