What can I do for you?
我可以为你做些什么?
What can it do for me?
它可以为我做什么?
If you can do it , so can I.
如果你能做到,我也可以。
can作为情态动词,表示<能,可以; 有可能;>,通常后面跟动词原形。比如I can speak more than three languages.(我能说3种以上的语言)
can可以作为动词,表示<将…装罐保存; 解雇;>,后面跟名词。比如When I got canned, I took these keys as souvenirs(我被开除后,就拿了这些钥匙作为纪念)
can可以作为名词,表示<罐子; 一听(的量); 喷雾器;>。比如A can is a metal container in which something such as food, drink, or paint is put(罐子就是一个用于装食物、饮料等的金属容器)