"so"主要引导结果状语从句，也可以与"that"连用，构成"so that"结构，表示目的或结果。例如：
1. She sang so beautifully that everyone was amazed.
2. They worked so hard that they finished the project ahead of time.
此外，"so"在某些情况下也可以引导目的状语从句，但这种用法不如"so that"常见。例如：
1. They bought a car so that they could travel more easily.
需要注意的是，当"so"表示"所以"的意思时，它通常不直接引导从句，而是作为连词，连接主句和从句，表达因果关系。例如：
1. So, he didn't come to the party.
综上所述，"so"主要引导结果状语从句，也可以与"that"连用引导目的状语从句，而单独使用时则表达因果关系。