一位微博网友想知道时间状语从句的时态遵循哪些规律。时间状语从句一般由 “while”、 “when” 和 “as” 等从属连词引导，与主句组成句子的整体。在这类句子中，主句和从句常对应哪些时态？不同的时态结构可以分别用来描述哪种情况？本期节目介绍引导时间状语从句的常见从属连词以及句子的时态。

（关于台词的备注: 请注意这不是广播节目的逐字稿件。本文稿可能没有体现录制、编辑过程中对节目做出的改变。）

BethHello and welcome to Question and Answer of the Week. I'm Beth. 

JiayingAnd I'm Jiaying. 本期节目中要回答的问题来自一位微博网友，问题由我来代读。 

Question我想问一下，时间状语从句的时态是怎么样的一种规律？ 

BethThank you for sending us your question! An adverbial clause of time is a subordinate clause, such as 'while I was walking', and must be in the same sentence as a main clause, 'my phone rang'. Adverbial clauses are introduced by a subordinating conjunction, like 'while' and they tell us when something happened. 

Jiaying是的。在 “While I was walking, my phone rang.” 这句话中，时间状语从句 “while I was walking” 与主句 “my phone rang” 构成句子的整体。

时间状语从句由像 “while” 这样的从属连词引导，用来说明事情发生的时间。接下来，我们就重点讲解三个常见的从属连词：“while”、“when” 和 “as”，以及它们一般用于哪些时态的句子中。

Beth'While', 'when' and 'as' can all be used when talking about actions or situations that happen at the same time. 

Jiaying这三个从属连词的意思都是 “在…的时候，与…同时”，而且都可以用来引出一件事情发生的时间段或背景情况。请听一段对话，在对话的答句中分别使用了 “while”、“when” 和 “as”。

ExamplesDid you answer the phone?（你接电话了吗？） 

No. He called me while I was leading a meeting.No. He called me when I was leading a meeting.No. He called me as I was leading a meeting.（我没接。他在我主持会议时打电话给我。） 

Jiaying在对话的答句中，描述事情发生的时间段或背景情况的从句是过去进行时，也就是 “I was leading a meeting”，主句中描述的动作 “he called me” 是一般过去时，说明 “他给我打电话” 这个动作是在说话人主持会议的时间段内发生的。

Beth'While', 'when' and 'as' must always be at the beginning of the adverbial clause, but this can go at the beginning or middle of a sentence. 

Jiaying没错，从属连词必须位于从句的句首。在上面对话的答句中，从句在主句后，因此从属连词位于整句话的中间。“主前从后” 的顺序常见于英语口语交流中。

BethIn writing, having them at the beginning or the middle of a sentence is common.  

Jiaying在书面语中， “主前从后” 和 “从前主后” 的情况则都很常见。听三个例句，时间状语从句的从属连词都位于整句话的句首。

ExamplesWhile I was leading a meeting, he called me.When I was leading a meeting, he called me.As I was leading a meeting, he called me.（在我主持会议时他打电话给我。） 

BethLet's look at some other examples of the past continuous and past simple. Here's one. 

ExampleAs I was driving past the school, I noticed a queue of people outside a shop.（当我开车经过学校时，注意到了一家商店外面排着长队。） 

Jiaying在这句话中，“我” 正在开车经过学校，也就是 “I was driving past the school”，“driving” 是一个延续性动作，从句的时态是过去进行时。这句话的意思是 “我在开车的过程中，注意到了商店外面的长队（…noticed a queue of people outside a shop）”，“noticed” 是非延续性动词，主句为一般过去时。再来听一个例句。

ExampleThe doorbell rang when we were eating dessert.（当我们正在吃甜点的时候门铃响了。） 

BethSo, they were eating dessert, 'the longer action', and were interrupted by the shorter action, 'the doorbell rang'. 

Jiaying在这句话中，“eating dessert（吃甜点）” 是一个持续时间较长的延续性动作，这个动作被持续时间较短的动作 “rang（门铃响了）” 所打断。 

BethNow, let's look at some other tenses we can use. 

Jiaying除了上面介绍的时间状语从句的时态以外，从属连词 “while” 和 “as” 还可以引导一般现在时或一般过去时的从句。

BethThis is especially true when the main verb refers to a continuous action or state, such as 'sit', 'lie' or 'wait'.

Jiaying没错，当主句中的谓语动词是 “sit”、“lie”、“wait” 这样的持续性动词时，从句时态通常是一般现在时或一般过去时。听两个例句。 

ExamplesWhile we wait for the rain to stop, the children can play inside.（我们在等雨停时，孩子们可以在里面玩。）

As I sat in the garden, a bee landed on my finger.（当时我坐在花园里，一只蜜蜂落在了我的手指上。） 

Jiaying还有一种情况：从属连词 “while” 和 “as” 引导的从句及其主句都是过去进行时。

BethThis means that two actions were happening at the same time in the past and have finished now. It's often used when telling a story. 

Jiaying这种结构通常意味着两个动作在过去的某个时间点同时发生，而且动作均已结束，通常用于向他人叙述一件过去发生的事情。听两个例句。

ExamplesAs I was walking towards him, he was walking towards me.（我向他走去时，他也向我走来。） 

While the adults were chatting, the children were running around.（大人们聊天时，孩子们跑来跑去。） 

BethIt's also possible to use two present perfect continuous clauses together, usually only with 'while'.

Jiaying我们一般只用 “while” 引导这类从句，也就是时间状语从句及其主句都是现在完成进行时的结构，这个结构用来谈论最近同时发生过的两个延续性的动作，在口语中比在书面语中更常见。来听两个例句。

ExamplesWhile I've been working hard, you've been drinking coffee!（在我努力工作的时候，你却一直在喝咖啡！） 

We're exhausted. I've been painting all day while he's been gardening.（我们已经累得筋疲力尽了。我一整天都在画画，而他一整天都在修整花园。） 

BethOK, Jiaying. Let's summarise. 

Jiaying好的。在谈论较长时间段内发生的持续时间较短的动作时，用从属连词 “while”、“when” 和 “as” 引导过去进行时的时间状语从句。 

从属连词 “while” 和 “as” 还可以引导一般现在时或一般过去时的从句。在强调两个动作在过去的某个时间同时发生，而且动作均已结束的时候，这两个从属连词所引导的从句及其主句也可以都是过去进行时。

最后，在谈论最近同时发生过的两个延续性的动作时，一般只能用 “while” 来引导现在完成进行时的从句，主句同样是现在完成进行时。

BethRemember, if you have a question about the English language you'd like to ask us, please send us an email. Our email address is: [email protected]  

Jiaying你也可以通过微博向我们提问。我们的微博账号是 “BBC英语教学”。Bye, everyone.

BethBye!