ENG文法~高人指點--------------------------------!

Ahh...it isn't wrong in today's world of English as it's been influenced by all sorts of things, including mirgrants and how they speak in order to get the message across! Although this would be quite wrong in written English.
The correct ways in written form are:
1) I helped by giving a hand.
2) I helped to give a hand.
3) I gave a hand.
4) I helped.
So the sentence you have there is in fact (2) without 'to' as in conversations these days, people are lazy and cut out alot of prepositions. Like these days i might say 'I'll put that into store' = 'I'll put that into the store room'. It's short and straight to the point - BUT I'd never write like that.
Hope that helps.

I helped giving a hand..
吾肯定- -''

錯~
should be: I helped to give a hand