1.You are not passers-by for each other.
*过客:passers-by.复数加到passer上。
2.The memory for each other is too much to forget.
*直译“痕迹”不好,我选择译成“回忆、记忆”。
*“不能相忘”,用too...to...句型,简单明了。
You are not passer-by..这句跟楼上一样。
the traces between each other are too deep to be forgotten.
You are not transient.Deep traces to each other can not forget.
You are by no means passerbys but attached tightly to my life with unforgettable memories.
You are not transient.pass-by usually used in oral english,to consider this sentense,you'd better choose transient.
We can't choose forget because of the deep mark.This sentence I translate it from the end to top.Because it can easily understand by the reader.Then,I use mark to instead trace because trace has many means,maybe reader will be puzzle.Memory is also ok ,because the mark between the us refer to it.
By the way,it translated by myself.
You are not passers-by,and we can never forget the contacts between us for it is so deep.