Question

Как записать в правильной форме предложение
___you___your friends the birthday party? (to invite)

Answer 1

Did you invite your friends the birthday party?
Если мы ставим вспомогательный глагол в прошедшей форме(did) , то уже обычный глагол ставим в настоящем времени

Answer 2

Как записать в правильной форме предложение 
___you___your friends the birthday party? (to invite)

Did you invite your friends the birthday party? Past Interrogative 

Are you inviting your friends the birthday party? Present continuous Interrogative

Do you invite your friends the birthday party? Present Interrogative

Would do you invite your friend the birthday party? Present Conditional Interrogative

Will you invite your friend the birthday party? Future Interrogative

Would will you like invite your friend the party? Future Conditional Interrogative.