1. She said that if the weather was fine, she would go on a picnic with her friends

2. Mary asked me who I talked to when I had problems

3. Hoa said that she would help her mum cook dinner that night

4. Minh asked Phuong if he could meet her at 4.30 the next day afternoon 

5. Nga said that she was staying with her aunt and uncle in the suburbs

*Statement:

S + said + (that) + S + V_lùi thì

S + said + to + O + (that) + S + V_lùi thì

S + told + O + (that) + S + V_lùi thì

*Yes - No question: S + asked + (O) + if/ whether + S + V_lùi thì

*Wh - question: S asked + (O) + question word + S + V_lùi thì

*Lùi thì:

Quá khứ đơn → Quá khứ hoàn thành

Hiện tại đơn → Quá khứ đơn

Hiện tại hoàn thành → Quá khứ hoàn thành

Hiện tại tiếp diễn → Quá khứ tiếp diễn

Quá khứ tiếp diễn → Quá khứ hoàn thành tiếp diễn

Hiện tại hoàn thành tiếp diễn → Quá khứ hoàn thành tiếp diễn

will → would

can → could

may → might 

must → had to

shall → should

is/ am/ are going to → was/ were going to