请教 英语方面的 急

不是太合适，thanks for 表示为了。。。而感谢
可以这样说：
thank all the people who have helped me
thanks to those who have helped me

这样肯定是不对的啦
首先，thank sb for (doing) sth 因为某事而感谢某人 这是一个句式啊 所以for后面加的是原因。
你可以这样说
Thank everyone who helped me before. /who has ever helped me.
你这边所用的thanks是做名词的吧，名词短语就不能做句子啦，你或者可以这样说
I'd like to show my thanks to those who helped me before. /who have ever helped me.

相比之下，我觉得第二种会比较口语化，应该也比较适合你用吧。。还有曾帮助过的，你可以用简单的过去时，完成时我想应该也没啥问题吧。

Thank all the people who have helped me. === 比较常见的，也口语一点；

I appreciate the people who have helped me and tried to help me.

=== 比较正式，一般用于正式场合；

Thanks for every one who helped me
Appreciate for the people who helped me

Thanks to those who ever helped me.