Question

Last summer my friends visited his grandparents. Задать общий, специальный,разделительный вопрос и отрицание

Answer 1

Чуть подправила исходное предложение ("friend" вместо "friends").
Общий вопрос: Did my friend visit his grandparents last summer?
Специальный вопрос: When did my friend visit his grandparents?
Разделительный вопрос: Last summer my friend visited his grandparents, didn't he?
Отрицание: Last summer my friend didn't visit his grandparents.

Answer 2

Общий вопрос: Did your friends visit his grandparents last summer?

Специальный вопрос: Whose grandparents did your friends visit last summer?

Разделительный вопрос: Did your friends visit his grandparents or their own grandparents last summer?

Отрицание: My friends did not visit his grandparents last summer.