【since用什么时态】文章内容注意到：since 一词在英语中具有多种含义和用法，通常用于表示时间、原因和条件 。它可以用作介词或子连词 ， 根据上下文而有不同的解释 。
作为介词，since 表示某一特定事件或时间点之后的时间，常与完成时态连用，用于强调动作的持续性 。
- Since I moved to this city, I have met a lot of new friends.
- Since last week, I have visited my grandparents twice.
- I couldn’t attend the meeting, since I was feeling unwell.
- We had to cancel the trip, since it was raining heavily.
