Общий: Have the boys already made the bird-houses? Специальный: When did the boys make the bird-houses? Альтернативный: Have the boys made bird-houses or an aviary? Разделительный: The boys have already made the bird-houses, haven't they? Вопрос к подлежащему: Who has made the bird-houses?
Have the boys already made the bird-houses?
Специальный:
When did the boys make the bird-houses?
Альтернативный:
Have the boys made bird-houses or an aviary?
Разделительный:
The boys have already made the bird-houses, haven't they?
Вопрос к подлежащему:
Who has made the bird-houses?