当前位置:首页 >> >>

英语周报高中英语 Unit1 Tales of the unexplained Grammar and usage课件 牛津译林版必修2_图文

Present perfect tense & Present prefect continuous tense Look at the following sentences and try to explain why the tense is used in these sentences. 1. We have studied English for about five years. 2. They have lived there since 1990. 3. She hasn’t finished her homework yet. 4. Eric has just come back. 5. How long have you been here? 1. The form of the present perfect tense: We form the present perfect tense with have/has and the past participle of the verb. have (has) +过去分词 2. The uses of the present perfect tense: Justin has disappeared, so Kelly is very sad. Note: We use the present perfect tense to talk about things that happened in the recent past, but are connected to the present. I have not seen Justin since last Friday night. Note: We also use the present perfect tense to talk about something that started in the past and is still happening now. I haven’t seen you for ages. He has just gone out. It has been very cold lately. She has already finished her homework. He hasn’t seen her since the meeting. Note: We use the present perfect tense when the exact time of an action is not clear or important. We use it with time expressions such as: already ever for just lately never recently since yet We use already for affirmative statements, yet for negative statements. We use for + a period of time, since + a point in time. He has just gone out.(= He went out a few minutes ago.) I have just heard the news. (= Now I know the news.) Note: We use the present perfect tense to talk about actions that were completed only a short time ago. e.g. They say that they have been to America many times. Note: We can also use the present perfect tense for repeated actions, that is, we use the present perfect tense with the time expressions once/twice/three times… Look at the sentences and find the difference: Tom has rung up three times this morning. Now it is still in the morning. Tom rang up three times this morning. Now it is not still in the morning. Note: Actions occurring in an incomplete period might be indicated by today or this morning/afternoon/ evening/ week/ month/ year/ century or all day/night/week, all the time, always etc. Point out what tense or tenses are used in the sentences and the reasons why they are used. 1. We have studied English for about five years. We began to study it five years ago. 2. They moved to the south in 1990 and have lived there since then. 3. Eric left home last year and has just come back. 4. They bo