Form: It is formed with the present tense of the auxiliary verb have and the past participle (3rd column in the irregular verbs).
Examples:
Affirmative: subject+ have/has+ -ed/3rd column+complement
I have decided to leave tomorrow (regular)
She has decided to leave tomorrow
Negative: subject+ haven't/hasn't+ -ed/3rd column+complement
He hasn't decided to leave tomorrow
We haven't decided to leave tomorrow
Questions: (Question pronoun)+ have/has/haven't/hasn't+subject+ -ed/3rd column+complement ?
What has she written the email to Lucy?
Have you written the email to Lucy?
Hasn't she written the email to Lucy?
What haven't you written to Lucy?
Uses:
General: the present perfect describes past events which are connected to the present.
1) Experience in our life up to now (hasta ahora):
Ex: Have you visited any other countries?
Yes, I have been to Italy and France.
(There is no time expression because we are talking about a whole life experience, not individual events. if we wanted to say when the events happened we would use the past simple.)
2) An event in the past that has a result in the present.
Ex: Helen has broken her pencil
I have hurt my foot.
(There is no time expression because when it happened is not important. Our attention is on the present (Where is the pencil?/ I can't play football). If we wanted to say when the actions happened we would use the past simple.)
3) A situation that started in the past and continues until the present.
Ex: I have lived here for ten years.
I have often seen Jim with his dog in the park.
(Here there is a time expression, describing how long or how often something has happened.)
4) Completion: we often use the present perfect when we describe how many things are completed so far.
Ex: I have read a hundred pages of this book.
(An exact time is not mentioned).
TIME EXPRESSIONS
1) Ever/never: we use ever and never when we ask or talk about our experiences in life.
Ex: Have you ever eaten Japanese food? No, I have never eaten it.
2) Yet/so far and already: we use yet in questions and negative sentences. It has a similar meaning to so far (or up to now), which is used in questions and positive sentences.
Ex: Have you finished this book yet? No, I am on page 56.
How many pages have you read? I have read 56 pages so far.
- We use already in positive sentences to describe an action which happened before.
Ex: When are you going to finish your letter? I have already written it.
3) Just: we use just when we describe a very recent event.
Ex: Cathy has just phoned from the airport.
4) Frequency adverbs (always, often...): frequency adverbs that are used with the present simple can also be used with the present perfect.
Ex: He has always loved you. (a state)
We have often visited Spain (a repeated event)
5) For and since: "for" describes the length of a time period.
Ex: Tom has worked here for three months.
"Since" describes the point when the time period started.
Ex: Tom has worked here since July 10th.
Present perfect continuous
Form: It is formed with the present perfect of be and the -ing form of the verb.
Examples:
Affirmative: subject+ have/has+ been+ verb -ing+complement
Ex: I've been waiting here all morning.
She has been reading a book all the day.
Negative: subject+ haven't/hasn't+ been+ verb -ing+complement
Ex: I haven't been sleeping well recently.
She hasn't been doing the homework today
Questions: (Question pronoun)+ have/has/haven't/hasn't+subject+ -ed/3rd column+complement ?
Ex: What have you been doing lately?
Have you been doing your homework lately?
What has he been studying today?
Has he been studying in the library today?
Use:
1) The present perfect continuous, like the present perfect, describes past events which are connected to the present. But in the continuous form, there is a meaning of an action or situation in progress.
Ex: What have you been doing lately?
I've been working a lot.
Ho long have you been living here?
2) The present perfect continuous can emphasize the length of the time of the action.
Ex: I have been waiting here all the morning.
He has been feeling ill for weeks.
3) The present perfect continuous can emphasize that the action is temporary.
Ex: I have been staying in a hotel for the past month.
4) The present perfect continuous can be used for repeated actions.
Ex: I have been phoning her for days, but she is never at home.
5) The action meay be finished or conitnuiun, we only know by the situation.
Ex: Carlos has been studying English for two years and now he's stopped! What a shame.
Carlos has been studying English for two years. He is going to do an exam next year.
Typical expressions: all day, all morning, for days, for ages, lately, recently, since, for...
Present perfect simple or continuous?
1) Often there is a very little difference between the two tenses:
Ex: I have worked here for two years
I have been working here for two years.
I have lived here for two years.
I have been living here for two years.
2) We often use the present perfect if our attention is on the finished result, but the present perfect continuous if our attention is on the action.
Ex: I have written that email to Jackie. i was meaning to do it for ages.
I have been writing that email to Jackie and it's taken an hour! I am exhausted!
3) If we give details of how many or how much we do not use a continuous form.
Ex: I have written four emails.
I have done a lot of cooking and cleaning this afternoon.
4) Present simple or present perfect?
We use the present simple to describe habits or states in the present, but we use the present perfect to describe the time until the present.
Ex: I live in Prague (a permanent state-I always live there)
I have lived in Prague for two years (I arrived two years ago and still live there).
5) past simple or present perfect?
The past simple describes an event in a completed time period. The present perfect is used for a time period that includes the present.
Ex: I lived in Prague in the nineties. (Now I live somewhere else)
I have lived in Prague since the nineties (I still live there)
COME ON!!!!YES, YOU CAN!!!
No hay comentarios:
Publicar un comentario