引导目的状语从句的so that 可以用in order that 替换，意义无甚差别；若主句和从句的主语一致的时候还可以用so as to或in order to将其转换为简单句。如：

I got up early so that I could be in time for the morning exercises.

→ I got up early in order that I could be in time for the morning exercises.

→ I got up early so as to / in order to be in time for the morning exercises.

▲有时为了加强语气，in order that 从句或in order to短语还可以放到句首，但so that 和so as to却不行。如：

In order that I could be in time for the morning exercises, I got up early.

In order to be in time for the morning exercises, I got up early.