*在谈到已死去人的情况多用过去时：lao she was a great writer. my grandmother was kind to us.有时两种时态都可以用：brahms was/is one of the greatest representative of german classicalism.注：在口语中一般过去时有时可用来代替一般现在时，使语气变得婉转一些，例如在下面句子中用一般现在时或一般过去时都可以，但用过去时显得客气一些（带有更多商量的口吻）：do/did you want to see me？
i wonder/wondered if you could spare a few minutes. i want/wanted to ask if i can/could borrow your bike.
未完待续……让大家久等了。第一次自己敲键盘发帖子。好累呀。：（——3dnow「外语学习成员」
五、 现在完成时现在完成时由have的人称形式加过去分词构成。他的肯定、否定及疑问形式如下：i have read it. i have not read it. have you read it？
现在完成时表示现刻以前发生的动作或情况，可以是：1. 到现在为止的这一时期中发生的情况（可能时多次动作的总和，也可表示状态和习惯性动作）：we have opened up 200 mu of land this year. how many pages have you covered today？
i haven't seen him for many days. 2. 对现状有影响的某一已发生的动作：the delegation has already left. i have seen the film many times. the city has taken on a new look.注： 这个时态有时还可以表示过去曾发生过一次或多次的情况，也可以说是一种经历：all our children have had measles. man's hairs have grown white in a single might. he says that he has seen a meteor at some time.这个时态的基本特点是它和现在有密切的联系，或是讲迄今为止这一段时间的情况，或是讲一个影响现状的动作，这样它不是从时间上就是从后果上和现在联系起来。根据这个特点我们可以判断什么时候用一般过去时，什么时候用现在完成时：1. 当有一个表示过去某时的状语（包括when）时，不能用现在完成时：i saw her a minute ago. just now xiao lin came to see you. when did you get to know it？
2.当有一个表示到现在为止这段时间的状语时，多用现在完成时：up till now we have planted over 24，000 fruit trees. we haven't had any physical training classes this week. he has learned a good deal since he came here. 3.在用already， yet， just， as yet， ever， never这类副词作状语时，常可用现在完成时：this is the second game. they 've already won a game. have you got the plan ready yet？ –no， not yet. i've just received a money order. 4.在单独谈一个过去的动作，不涉及它对现在的影响时，通常用一般过去时，如果谈一件已经发生的事，不考虑它是什么时候发生的，而主要考虑对现在的影响，多用现在完成时：did you get up very early？
has he got up？
what did you have for lunch？
have you had lunch？
i got the news from xiao yu. i've got no news from him.注： 有since引起的状语时，主要谓语通常用完成时态：we met in 1972，and have been good friends ever since （then）。
it has rained a great deal since you left. we haven't seen each other again since them （since we parted in 1952）。 但在表示时间长度时可用一般现在时。
l 在使用一个表示状态的动词（如be， seem等）作谓语时，间或也可用现在时态：it's ok since i fixed it. it seems a long time since i was here. i'm getting interested in china since you came here. 间或用过去时，特别时在口语中。
i lost ten pounds since i started swimming.在since引起的状语从句中，通常用一般过去时。但间或可用现在完成时：i haven't seen him since i have been back. since i have known her， she has been fond of sports.有时同样一句汉语，由于使用场合不用，译成英语时可能需要不同时态：has xiao yang come？
