用于条件句时， be going to　表将来
　　　　　　　 will　表意愿
　　If you are going to make a journey¹, you'd better get ready for it as soon as possible.
　　Now if you will take off your clothes, we will fit the new clothes on you in front of the mirror.

上一篇：一般将来时 下一篇：be to和be going to