你知道since的八种用法有哪些吗？

since的八种用法详 since是英语中高频使用的词，兼具介词、连词和副词功能，用法灵活。以下从八个核心维度析其具体应用。 1. 介词：接时间点，表“自从……以来” 用法：后接具体时间点年份、月份、日期、时刻等，主句常用现在成时。 例：They have lived in this house since 2015. 例：I haven’t eaten since morning. 2. 连词：引导时间状语从句，表“自从……之后” 用法：从句用一般过去时，主句用现在成时，动作从过去持续到现在。 例：She has worked here since she graduated from college. 例：We haven’t spoken since he moved to another city. 3. 连词：引导原因状语从句，表“因为；既然” 用法：语气较弱，常置于句首，说明已知的原因。 例：Since it’s raining, we’d better stay indoors. 例：Since you don’t like spicy food, I’ll order a mild dish. 4. 副词：单独使用，表“从那时起；此后” 用法：指代前文提到的时间点，句中作时间状语。 例：He left his hometown in 2010 and hasn’t returned since. 例：I met her once in 2018, but we haven’t联系 since. 5. 与“ever”连用：ever since，表“从……一直到现在” 用法：持续性，可作连词或副词，语气比单独since更强。 例：Ever since she was a child, she has loved dancing. 例：He hurt his leg last month and has been in pain ever since. 6. 用于疑问句，询问“多久以来” 用法：搭配how long，回答需用since引导的时间状语。 例：— How long have you been learning piano? — Since I was six. 例：— How long has the store been closed? — Since last Friday. 7. 主句用现在成进行时，表动作持续且未 用法：动作从过去开始，持续到现在，且可能继续。 例：She has been teaching here since 2019. 例：They have been waiting for the bus since 8 o’clock. 8. 口语中省略从句主语和be动词 用法：当从句主语与主句主语一致且含be动词时，可省略从句主语和be。 例：He has changed a lot since (he was) a teenager. 例：We’ve been friends since (we were) in primary school.