在时态搭配上，since引导的从句需用一般过去时，主句则用现在成时。例如：
- She has worked here since 2018.
- I haven't eaten anything since I woke up this morning.
since还可用于"It is/has been+时间段+since从句"结构，表示"自某事发生以来已有多久"。如：
- It has been three years since we last met.
- It is five months since the project started.
二、ever since的功能
ever since是副词短语，由"ever+since"构成，动作从过去某点开始持续至今的延续性。它既可单独使用，也可接时间点或从句，主句必须用现在成时。
单独使用时，需前文已明确时间起点：
- He left his hometown in 2010 and has lived abroad ever since. 接时间点或从句时，语义相当于"since...until now"：
- They have kept in touch ever since that unforgettable night.
- She has been interested in astronomy ever since her father gave her a telescope. ever since比since具有更强的情感色彩，常隐含"从那以后就一直如此"。例如：
- The accident changed his life ever since.比用since更事件的深远影响 三、关键差异对比 | 维度 | since | ever since | |-------------|------------------------|-------------------------| | 词性 | 介词/连词 | 副词短语 | | 语气 | 客观时间起点 | 持续至今的延续性 | | 独立性 | 可单独引导从句 | 需依托主句存在 | | 搭配时态| 主现/从过去时 | 主句必须用现在成时 |
实际运用中，since多用于日常，ever since更适合文学表达或情感。例如： 1. Since the new policy was implemented, traffic has improved.客观描述 2. Ever since she lost her daughter, the mother has carried her photo everywhere.情感
语言的魅力在于精准表达，since与ever since如同时间轴上的不同刻度，前者标记起点，后者丈量绵延，唯有深入理其差异，方能让时间的叙述更加生动立体。