Sentence Correction

[sufdar]

Dear

I was going through the the english notebook of my daughter. I caught a sentence written by her teacher "How many cousins does Mr.Peter have"
and in the answer "Mr.Peter have three cousins"

I do no think the above sentences are grammatically correct
would you please help me

Thanks

Sufdar

[Casiopea]

Welcome, sufdar.

"How many cousins does Mr.Peter have"
Correction
How many cousins does Mr. Peter have?


"Mr.Peter have three cousins"
Correction
Mr. Peter has three cousins.

All the best.