I'd go back in time and change it but I can't.

我想回到当时，挽回一切，却无法回头。

youdao

After giving it a thought, I'd like to travel in a time machine, go back to the past and finish off the things which I haven't been able to finish in the past.

想想还是觉得我更喜欢拥有时间机器可以在不同时空穿梭，回到过去。把以前未完成的事情做完。

youdao

After giving it a thought, I'd like to travel in a time machine, go back to the past and finish off the things which I haven't been able to finish in the past.

想想还是觉得我更喜欢拥有时间机器可以在不同时空穿梭，回到过去。把以前未完成的事情做完。

youdao