`1.` They used to go to school by bike when they were young.

→ used to V: thói quen trong quá khứ

`2.` She started teaching her children to play the piano 4 years ago.

→ start doing sth: bắt đầu làm gì

→ started → thì quá khứ đơn → 4 years ago

`3.` I wish I could cook as well as my mom.

→ It's a pity: thật đáng tiếc

→ wish + qkđ: ước cho hiện tại

1.They often went to school by bike when they were young

->They used.to go to school by bike when they were young.

2.She has taught her children to pay the piano for 4 years

->She started teaching her children to play piano 4 years ago.

3.It's a pity I can't cook as well as my mom

->I wish I could cook as well as my mom

CT:S1+ wish+ S2+ V(lùi thì).

used to + V: đã từng làm gì.

S+started+P2/Ving/+O+for/since...