请问“i think it's favour for you to do that"语法是否有误

有一点错误,应该:
I think it's a favour for your to do that.
虽然没有上下文,但我觉得如果用以下说法会更好:
Please do me a favour to do that.
补充："我认为你那样做对你有利" This is favorable for you ( to do that ).