首先我们来看下since和since that的大致意思：
since：词性为介词，自从某一时刻或特定事件之后的一段时间
since that：词性为连词，由于某个具体的原因
通过下面的表格我们了解下since和since that的含义、发音和用法
接下来让我们看下since和since that的用法区别：
1.词性：since是介词，而since that则是连词
例子：
- Since you left, I have been living alone.
(Since你离开以后，我就一个人生活了。)
- Since that you are already late, we can start now.
(Since that你已经迟到了，我们可以开始了。)
2.含义：since表示从过去某一时刻到现在的延续性，而since that表示因为某个具体的原因
例子：
- I saw his face and since he may not be in a good mood.
(我看见他的脸色不好，since心情可能不太好。)
- Since that we only have one car, we need to plan our travel time wisely.
(Since that我们只有一辆车，我们需要合理安排出行时间。)
3.发音：since和since that在发音上没有区别
例子：
- Since that accident, he has never dared to drive again.
(自从那次事故以后，他就再也不敢开车了。)
- Since you are back home, I will tell you the result.
(Since你回家之后，我会告诉你结果。)