Краткий ответ
Do their grandparents live in the country?
Where do their grandparents live?Do their grandparents live in the country?
Who live in the country?
Здесь who заменяет множественное подлежащее their grandparents. Также встречается вариант Who lives in the country?Does Liz go for a picnic every month?
When does Liz go for a picnic?Did Ann run with her brother yesterday?
Who did Ann run with yesterday?Is my sister picking flowers now?
What is my sister picking now?Was his friend at summer camp last month?
Where was his friend last month?Does her uncle hunt every summer?
When does her uncle hunt?
Точнее по смыслу: How often does her uncle hunt?
Как образуются вопросы
Present Simple:
Do/Does + подлежащее + глагол
После does глагол ставится без окончания -s:Does Liz go, а неDoes Liz goes.Past Simple:
Did + подлежащее + начальная форма глагола
Поэтому:Did Ann run, а неDid Ann ran.Глагол to be и Present Continuous: глагол ставится перед подлежащим:
Was his friend...?,Is my sister picking...?В вопросе к подлежащему вспомогательный глагол обычно не нужен:
Who live(s) in the country?
