How much I have to pay for the dinner?

[Dharminder Singh]

How much I have to pay for the dinner?

Is the above sentence grammatically correct?

 

[5jj]

No.

How much do I have to pay for the dinner?

 

[Dharminder Singh]

No.

How much do I have to pay for the dinner?

Please explain why "do" Is necessary?

 

[emsr2d2]

Please explain why "do" is necessary?

That would require more time and effort than we are able to give here. You need to study auxiliary verbs. "Do" is one of them. Read more HERE.