Общий вопрос: Did my mother write a letter yesterday?
Специальный вопрос: What did my mother write yesterday?
Отрицательная форма: My mother did not write a letter yesterday.
Общий вопрос: Did my mother write a letter yesterday?
Специальный вопрос: What did my mother write yesterday?
Отрицательная форма: My mother did not write a letter yesterday.