1) They saw Marina yesterday.
Did they see Marina yesterday? - Общий вопрос.
Whom did they see yesterday? - Специальный вопрос.
2) His little son liked to ride a bike last summer.
Did his little son like to ride a bike last summer? - Общий вопрос.
What did his little son like to do last summer? - Специальный вопрос.
3) His father was in America last year.
Was his father in America last year? - Общий вопрос.
When was his father in America? - Специальный вопрос.
4) They were in the Kremlin last week.
Were they in the Kremlin last week? - Общий вопрос.
Where were they last week? - Специальный вопрос.