目录
Since的用法 — 时间
连接词
副词
介系词
Since的用法 — 原因
练习题
比较Since,for
比较 Since,because,as
练习题答案
Since的用法
Since分别有两种涵意:时间和原因。我们可以依照句子语意、结构和时态,决定since在句子中的意思。
1. 时间
在时间的层面上,与「自从」有相似的意思。 Since通常可作为介系词代入一个片语、或连接词代入一个子句、或是以副词单独存在。另外,since后的子句大多是过去式,主要子句为完成式。
连接词
当since用作连接词时,可搭配一段期间或某个时刻,引导时间附属子句,意为「自从…」。附属子句,即 since 子句,的动词通常为过去简单式或现在完成式,而主要子句则使用现在完成式或过去完成式,但以现在完成式居多。如要表示一段期间,since子句该为现在完成式;如要表示某个时刻,since子句便为过去简单式。不论是过去简单式还是现在完成式,意思大致上相同。
【例】I haven’t done any outdoor activities since I graduated from university.
【例】John had been cooking his own dinner since he was twelve years old.
在另一种清况下,当主要子句的结构为”It + be + 时间 + since”,可以以四种不同的句型构成,但意思绝对相同。主要子句的be以现在简单式 is或现在完成式 has been,而附属子句则为过去简单式或现在完成式。在美式英语中,” It has been… since…” 比较常见。
【例】It is ten months since Paul and Linda moved to a new apartment.
【例】It is ten months since Paul and Linda have moved to a new apartment.
【例】It has been ten months since Paul and Linda moved to a new apartment.
【例】It has been ten months since Paul and Linda have moved to a new apartment.
其实在刚刚说明的结构中,be亦可使用过去简单式 was 或过去完成式 had been,但此时 since 子句须使用过去简单式或过去完成式。
【例】It was ten months since Paul and Linda moved to a new apartment.
【例】It had been ten months since Paul and Linda had moved to a new apartment.
当 since 不是引导过去某个动作或事件,而是过去的某个状态并现在一直持续着 ,主要子句及其附属子句都要用现在完成式。
【例】Tom has been sleeping less than 4 hours every day since he has become a doctor.
副词
作为时间副词,since/since then有着「此后,从此,自那以后」的意思。
而ever since能用来加强since和since then的语气。
【例】We graduated from secondary school a year ago and we haven’t reunited since/since then.
【例】They divorced few months ago and haven’t contacted each other ever since.
介系词
作为介系词时,since只能与某一时刻搭配,即是since之后必须接着日期、年份等时间有关的词。时刻能以副词(e.g. yesterday)、名词片语(e.g. the beginning of the match)或动作动词(e.g. I left)表示。意为「自从…,自…以来,从…至今」。
【例】Since yesterday, I haven’t eaten anything.
【例】Since the beginning of the match, she has been cheering loudly for her teammates.
【例】Since I left my previous workplace, it has become much quieter than before.
在某种情况下,我们可以将since从连接词变成介系词—就是当 since 子句和主要子句的主词(subject)是相同时,便可省略 since 子句的主词。这样,本身句中的主动词须改为动名词 ,接在since后。
【例】Since attending tutorial classes, I have become more confident when answering questions during lessons.
(原句:Since I have attended tutorial classes, I have become more confident when answering questions during lessons.)
2. 原因
除了在时间方面,since 亦可作为连接词,引导表示原因的附属子句,意为「既然」。 Since接着的子句通常是现在式,亦能是整个前后子句都为过去简单式。放在主要句子前或后都同样没问题。 Since的运用大多想表达显而易见或已成事实的原因。
【例】Since it is too cold out there, I will just stay home today.
【例】Since the power is out, we should just go to bed directly.