Bluesky’s answer is quite decent. Here is a shorter version and it’s also what I would say. It’s been an honor to work with you. 和你共事是我的荣幸。 Bon voyage and have a prosperous future. 祝你一路顺风，前程似锦。 Take care. Good-bye. 保重。后会有期 I’m not sure if a little literal translation will help. Anyway, here it is: 和你(with you) 共事(together work) 是(be) 我的(my) 荣幸(honor)。 Think of it as “Working together with you is my honor”. 祝你(Wish/May you) 一路(all the way) 顺风(downwind) This phrase derives from sailor talk. ，前程(ahead trip) 似锦(like embroidery)。 Think of it as “The trip ahead is like embroidery/embroidery-like.”. When joining two sentences, we often just use a comma for “and”. And you know how life is often described as a trip, right? Chinese employs tons of metaphors. And this embroidery thing is a metaphor for being bright and promising because embroidery tends to be colorful (therefore bright) and in old days it took a rich person to get to have it (therefore promising). 保重 (Protect (and) cherish (your body))。 Predictable parts in commonly-used phrases will usually be left out. 后会 (later encounter) 有(have/there be) 期(time/date) Think of it kind of as a backward version of “There will be a time for us to meet again”. I can record this on mp3 email it to you if you want. ^_^

You may say like this: 和你共事的这段日子已成为我心中美好的回忆。 愿你前程似锦，永远开心。 保重，后会有期！

以下是楼上回答的拼音版本 "he ni gong shi de zhe duan ri zi yi cheng wei wo xin zhong mei hao de hui yi yuan ni qian cheng si jin yong yuan kai xin bao zhong, hou hui you qi."