English

1. past continuous : describe an action which happened for sometime and and stopped when something else happened:

ex : They were playing tennis when we arrived , he was watching television when the lights went out

The past continuous

The past continuous is often used to describe an action which happened for some time and then stopped when something else happened:

He was watching television when the lights went out.

The past continuous is also used to describe an action that went on for longer than something in the past simple:

He was still studying at university when he got married.

2. Past perfect : Past perfect = had + past participle : describe an action which happened before another action in pact

ex He missed the train because he had overslept.(First he overslept, then he missed the train.)

He didn't get a table at the restaurant because he had forgotten to book one. (First he forgot to book the table, then he didn't get a table at the restaurant.)

The past perfect

The past perfect describes an action which happened before something which we are already describing in the past:

He missed the train because he had overslept.

He didn't get a table at the restaurant because he had forgotten to book one.

3. Past simple or present perfect simple or continuous?

'I ran, I've run, I've been running'

The past simple:
We use the past simple to talk about complete events that happened in the past:

I'm very happy because yesterday Julia telephoned me and said she loved me.

Remember if we say 'when' something happened we must use the past simple.

The present perfect
We use the present perfect to talk about something that began in the past but is still true now:

I've known Julia for 3 years.

And when we are interested in the fact, not the moment when it happened.

We've decided to get married.

The present perfect simple also acts as a bridge between the past and the present:

Have you ever fallen in love?

- we are talking about sometime in a person's whole life.

The Present Perfect Continuous
We use the present perfect continuous to talk about an activity repeated many times up to now.

We've been discussing the wedding all week.

And to emphasise an action:

Julia's mother has been following our discussions with interest.

If we say 'she has followed …', she is more interested in the result of the discussions.

Modals of obligation and permission

'Must' is used to express an obligation which the speaker agrees with:

You must study all this weekend for an exam on Monday.

'Have to' is used to express an obligation which has been imposed by someone else:

Question: Can you come out with me tomorrow?
Answer: I'm sorry. I have to study all weekend. I've got an important exam on Monday.

'Mustn't' means 'not allowed to':

You mustn't start writing till I say.

'Don't have to' and 'needn't' mean it is not necessary:

There are ten questions, but you don't have to answer them all.
You must answer at least five questions, but you needn't write more than 500 words for each answer.

'Must' doesn't have a past tense instead you use 'had to':

Question: Why are you looking so unhappy?
Answer: Because my boyfriend had to study all weekend.

Instead of 'mustn't' you use 'wasn't / weren't allowed to':

Quesion: Can I see your exam?
Answer: I'm sorry. I wasn't allowed to take it out of the exam room.

'Can' is used to ask for and give permission:

Question: Can I borrow your notes, please? I'll have the same exam next week.
Answer: Yes, of course you can, but you mustn't lose them!