`1)` `(-)` Nam didn't write an essay in Literature class this morning.
Công thức câu phủ định ở QKD:
S + didn't + v_infinite + ...
VD: I didn't go to school yesterday.
`1)` `(?)` Did nam write an essay in Literature class this morning?
Công thức câu nghi vấn ở QKD:
Did + S + v_infinite + ...
Did i go to school yesterday?