精选优质文档-倾情为你奉上现在完成时【概念引入】欣赏含有现在完成时的名言：Life has taught me to think, but thinking has not taught me to live. 生活教会了我思考，但思考却没有教会我生活。Winter must be cold for those with no warm memories. We have already missed the spring. 对于那些没有温馨回忆的人们来说，冬天一定很冷。我们已经错过春天了。Nature has given us the seeds of knowledge, but not knowledge itself. 在自然赋予我们知识的种子，而非知识本身。现在完成时的构成：现在完成时是：助动词have（has）+过去分词构成的。I have finished my homework. 我已经完成了作业。现在完成时的否定句：是在助动词have(has)的后面加not构成。I havent seen the
