i can't help repair

那个是can't help doning 是忍不住的意思
而这里仅仅是帮忙的意思就用原形

helpsb. with sth.

help sb. do sth,

那是就近原则 help do sth
有个短语:can't help doing sth(情不自禁做某事) 你那句子用那短语没法翻译 只得用就近原则

i am busy now, so i can't help repair - 错的

i am busy now, so i can't help to repair ...
这样就可以

.....请问你学过英语没啊!!!!help doing sth的意思是禁不住做某事，help do sth是帮助某人做某事的意思