provided(或providing)是连词，supposing(或suppose)也可作连词，英文意思都是if,但是实际上两者含义不同。provided(或providing)用来表示条件，supposing(或suppose)用来表示假设。supposing(或suppose)的含义是：Whatwould/willhanppenif...?，所以常用在问句中。用法上也有区别，provided(或providing)后面可加that,也可以不加，意思还是一样，supposing(或suppose)后面不加that.
