Ответ:
Exercise 1:
1) He helped his mother yesterday.
2) My mother bought milk last week.
3) I could swim very well last week.
4) She played basketball two days ago.
5) We washed our hands three hours ago.
Exercise 2:
1) I didn't drink juice yesterday.
2) My friend didn't watch TV last week.
3) She didn't grow flowers last year.
4) The children didn't clean their teeth yesterday.
5) He didn't give me his toys.
6) They didn't jump very well yesterday
Объяснение:
Past Simple:
Положительное:
S+V+ed (или же неправильный глагол в прошедшем времени; кратко: V²)
Отрицательное:
S+didn't+V (V¹; начальная форма)
Вопросительное:
Did+S+V (V¹)
В Exercise 1 последнем предложении можете заменить two hours ago в yesterday если понадобится.