大家帮我译一句话,你是世界上唯一了解我的人用英语怎么说?you are the only one know me in the world?我晕了，可到底哪一个呀？you are the only one who understand me in the world?

you are the only one who understand me all over the world

you are the only one who understands me in the world.
who是第三人称单数，因为前面是you are所以是一般现在时，动词understand后面需要加s。
in the whole world严格上来说是不太正确的，因为world已经是全世界的意思了。

You are the only one who understands me in the world.

You are the only one who knows me in the world

You are the only person who understands me in the whole world.
understand比know更合适

也可以说 you are the only one understands me in this world.

you are the only one who understands me in the world
定语从句缺主语，关系代词不省，know知道understand理解，了解
不好意思s忘记打了