We use the present perfect to show that something has continued up to the present

They’ve been married for nearly fifty years.
She has lived in Liverpool all her life.

… or is important in the present:

I’ve lost my keys. I can’t get into the house.
Teresa isn’t at home. I think she has gone shopping.

We use the present perfect continuous to show that something has been continuing up to the present:

It’s been raining for hours.
We’ve been waiting here since six o’clock this morning.

We use the past perfect to show that something continued up to a time in the past:

When George died he and Anne had been married for nearly fifty years.

... or was important at that time in the past:

I couldn’t get into the house. I had lost my keys.
Teresa wasn’t at home. She had gone shopping.

We use the past perfect continuous to show that something had been continuing up to a time in the past or was important at that time in the past:

Everything was wet. It had been raining for hours.
He was a wonderful guitarist. He had been playing ever since he was a teenager.

We use will with the perfect to show that something will be complete at some time in the future:

In a few years they will have discovered a cure for the common cold.
I can come out tonight. I'll have finished my homework by then.

We use would with the perfect to refer to something that did not happen in the past but would have happened if the conditions had been right:

If you had asked me I would have helped you.
I would have helped you, but you didn’t ask me.
You didn’t ask me or I would have helped you.

We use other modals with perfective aspect when we are looking back from a point in time when something might have happened, should have happened or would have happened.

The point of time may be in the future:

We’ll meet again next week. We might have finished the work by then.
I will phone at six o’clock. He should have got home by then.

the present:

It’s getting late. They should have arrived by now.
He’s still not here. He must have missed his train.

or the past:

I wasn’t feeling well. I must have eaten something bad.
I checked my cell phone. She could have left a message.

 


 

Section: 

Comments

which one is correct: He is going to make a trip around the world / He is going to take a trip around the world ?

Hello Mehnaz Rashid,

The correct verb here is 'take'.

Best wishes,

Peter

The LearnEnglish Team

Dear sir, i want to tell.. an action should be happened in the past. But it is not happend yet..
How do i tell

Hello salmal,

If I understand your question correctly then you want to describe an action which you expected in the past but which did not happen. There are several ways to say this, but I think the one you might be looking for is 'should have', followed by the third form of the verb (the past participle). For example, let us say that I expected my friend to arrive in London yesterday but he is still not there. I might say this:

My friend should have arrived in London yesterday.

 

Best wishes,

Peter

The LearnEnglish Team

Thnk u sir...
Can i tell..
We should have memorized this in the age of 12..but we have not memorized yet.
And .. can we use must have instead of should have..
I hope u will understand my question.thnk u

Hello salmal,

That sentence looks fine to me. You can't use 'must have' in this context, however. If you were talking about a rule or law which you did not follow then you could use 'supposed':

We were supposed to arrive at 8.00 but we were late.

 

Best wishes,

Peter

The LearnEnglish Team

. Having fought so long against a repressive government, they were aware of how easily power" is used" to crush free thought, open discussion, and civil rights......I think instead of" is "here "could be "be used because sentence is in past tense so complete sentences should be in past.i am confused because I read somewhere that we need to maintain the tense of sentences in the whole sentence..... please help me

Hello Rakesh Kumar,

You can use either 'is' or 'could be' in this sentence. Other forms are also possible:

Having fought so long against a repressive government, they were aware of how easily power is used to crush free thought, open discussion, and civil rights

 

Having fought so long against a repressive government, they were aware of how easily power has been used to crush free thought, open discussion, and civil rights

 

Having fought so long against a repressive government, they were aware of how easily power had been used to crush free thought, open discussion, and civil rights

 

Having fought so long against a repressive government, they were aware of how easily power could be used to crush free thought, open discussion, and civil rights

Amongst others. There is no particular rule here; the normal logic of tense use applies, just as in any other sentence.

 

Best wishes,

Peter

The LearnEnglish Team

Sir may you tell me the rules about when we need to maintain the tense of a sentence. tell me when and where this rule is applicablethis .May you illustrate this with some examples.as far as I am able to recall my English teacher told me this rule while teaching narration. Sir I am really confused about this rule while. In the first sentence use of IS is wrong or right if it is right then how we are maintaining the tense of sentences or there is no such rule about maintaining the tense of sentences.

Hello Rakesh Kumar,

All of the examples I posted were correct and possible sentences. There is no rule about which tense needs to be used here; it depends entirely on what the speaker wishes to say. For example:

Having fought so long against a repressive government, they were aware of how easily power is used to crush free thought, open discussion, and civil rights.

We use is used in this example because we are talking about something which happens around the world regularly. This is a normal use of the present simple.

Having fought so long against a repressive government, they were aware of how easily power has been used to crush free thought, open discussion, and civil rights.

We use has been used because we are talking about something which was done in the past and has a current effect. This is a normal use of the present perfect.

Having fought so long against a repressive government, they were aware of how easily power had been used to crush free thought, open discussion, and civil rights.

We use had been used because we are talking about something which happened in the past and had an effect on another event in the past. This is a normal use of the past perfect.

Having fought so long against a repressive government, they were aware of how easily power could be used to crush free thought, open discussion, and civil rights.

We use could be used because we are talking about something which is possible but not certain in the future. This is a normal use of the modal verb could.

 

The point is that the tenses use are simply normal tenses, with their normal meaning. Which form is used depends on the intention of the speaker and the situation which they are describing. It is a matter of choice, not grammar requirement.

 

Best wishes,

Peter

The LearnEnglish Team

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