Section Ⅳ　Grammar & Writing

　　现在完成时

　　观察下列从Reading and Vocabulary中选取的句子，体会现在完成时的用法。

　　1．It's been six years since we last saw each other，you know.

　　2．And this is the first time I've visited your hometown.

　　3．You know，I've seen quite a lot of China and I've visited some beautiful cities，but this is one of the most attractive places I've been to.

　　4．My wife's just bought a beautiful dress from one of the shops there.

　　5．A friend's told me about a nice little fish restaurant near here.

　　一、现在完成时的构成

　　基本形式：have/has＋动词的过去分词

　　否定形式：have/has＋not＋动词的过去分词

　　被动形式：have/has＋been＋动词的过去分词

　　二、现在完成时的用法

　　1．表示过去发生的动作对现在造成的影响或结果。常与recently，before，lately，just，already，yet，so far，up to now，till now，in the past/last ...years，these days等时间状语连用。

　　-Have you had lunch yet?

　　你(已经)吃午饭了吗？

　　-Yes，I have.I've just had it.

　　是的，我吃了。我刚刚吃过。(现在我不饿了)

　　He has been there three times in the last few years.

　　近几年他去过那里三次了。

　　2．表示动作或状态过去已经开始，持续到现在(可能还会继续进行下去)。常与表示一段时间的时间状语连用如：for＋一段时间，since＋过去时间点，since then，ever since，up to now，so far等。

　　Mr.Wang has worked in this factory since he came to this city.

　　自从到这个城市以来，王先生一直在这家工厂工作。

She has taught in the school for ten years.