a)- Did he help his mother?
Yes, he did (ou) Yes, he helped his mother.
b) - Did they play soccer?
Yes, they did (ou) Yes, they played soccer.
c)- Did the dog drink milk?
Yes, it did (ou) Yes, the dog drinked milk.
d)- Did she clean the house?
Yes, she did (ou) Yes, she cleaned the house.
