2011.9.15动词时态（完成时）

nullnullwill和 be going to：“迹象”“打算”going to, 临时想起用will。 1.Look at the clouds. It looks as if it’s going to rain. 2.---the phone is ringing. ---I’ll answer it. 3. ---Have you sent him the email? ---Oh, I forgot. Don’t worry. I’ll send it right now.主从句时态： 主将从一很常见，从句will(would)不出现。 从句可用be to do，安排或打算。 In such dry weather the flowers will have to be watered if they __________. A. have survived B. are to survive C. would survive D. will survivenull现在完成时： 动作影响或持续，since主完从过去； in the past few years, 某人做事第几次； Up to now till/by now, before， recently， so far, 现在完成常连它。说明：1.动作影响或持续：过去发生的动作对现在造成影响或后果，或者过去某一时间开始并一直持续到现在的动作或状态。这是现在完成时的基本用法条件，只要符合这两个条件之一，动词就用现在完成时。 示持续的动作或状态往往与表示一段的时间状语连用.例如: I have been here for just over two years. 我到这里才两年多. He has worked here since 1989. 从1989年, 他就在这里工作. 注意，句子中有一段时间，动词不一定用现在完成时。 He stayed in USA for 2 two years and came back last year. (在美国停留并没有持续到现在，所以动词stay用一般过去时)null2.since主完从过去： since从句用一般过去时，主句用现在完成时。 She has worked as a nurse ever since she left school three years ago . 她三年前毕业,从那时起便一直当护士。 3.某人做事第几次: 固定句型：It is the first/second time that sb has done sth. It was the first/second time that sb had done sth. 4. in the past few years，over/during the past /last few years/months, By now， till now，before单独用，recently lately, so far, 如果句子有这些时间状语，动词常用现在完成时。 (但in the past常常和一般过去时连用。时间名词+before，动词用过去完成时)。nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull