1、现在完成时的构成：现在完成时是由“助动词have/has+动词过去分词”构成的。①助动词have/has可以与主语缩写为’ve/’s。e.g. I have → I’ve We have → We’ve He has → He’s It has → It’s②规则变化的过去分词与动词过去式一样。③不规则变化的动词过去分词见表。2、现在完成时的基本句型。①陈述句肯定形式。e.g. I have had lunch. 我已经吃过午饭了。He has gone to Beijing. 他去北京了。②陈述句否定形式。(在助动词have/has后+not，可缩写为haven’t/hasn’t)e.g. I haven’t had lunch. 我还未吃午饭。He hasn’t gone to Beijing. 他还没有去北京。③一般疑问句形式及其答语。(将助动词have/has提前，答语一般用have, has回答)e.g. Have you had lunch? 你吃过午饭了没? Yes, I have. No, I haven’t.Has he gone to Beijing? 他去过北京了没有? Yes, he has. No, he hasn’t.否定回答还可以用：No, not yet. / No, never. / No, not even once等。④特殊疑问句形式。(疑问词+一般疑问句)e.g. Where has he gone? 他去了哪里?