so that引导目的状语从句时,表示“以便；为了”,从句中常使用can /could /may /might /will /would /should等情态动词或助动词；引导结果状语从句时,从句中一般不用can和may等词,在so that前可以用逗号,意思是“因此;所以”.如：
1. The little boy saved every coin so that he could buy his mother a present on Mother's day.
2. She bought a digital camera online so that she would save a lot of time.