You seem thinner/fatter. 你瘦了,是指对"你"的感官,所以用seem.对人说你瘦了,说明你以前见过这个人,"瘦"是和以前状态的比较所以我们用thinner/fatterIf you are free,i want to meet you.free有空闲的意思,一般说你...