⇒Lien told me she was going shopping with her mother the next day.

Form: S1+ told/said+ S2+ V lùi thì ; tomorrow→the next day

⇒My sister asked if you had moved the previous day

Form: S1+ asked O + if/whether+S2+ V( backward)

I will go shopping with my mother tomorrow . Lien said
=> lien said that she would go shopping with her mother the following day
CT: S + said/told+) +S2 + V (lùi 1 thì): my -> her, tomorrow-> the following day

did you clean this room yesterday? My sister said
=> my sister asked me if i had cleaned that room the previous day
CT : S+ asked + O +if/whether+ S2+ V (lùi 1 thì) ; yesterday -> the previous day
chắc vậy, sai đâu thì bảo mk
@sakurazuka