The Helping Verbs

*The auxiliary verbs help the main verb.We also call them the helping verbs.By using helping verbs ,we can negate sentences and form questions.We can't do without helping verbs.The auxiliary verbs (helping verbs) are used as a main verb or as a helping verb in sentences.As a main verb ,they stand alone.But as a helping verb,they are followed by a  verb.The auxiliary verbs are :be,have and do.


1-Verb to "Be"

• present simple(am-is-are)
• Past simple (was-were)
• Past participle (been) 

Ex:I am an English teacher.(main verb)
EX:He is ill.(main verb)
EX:They are absent.(main verb)
EX:She was at school.(main verb)
EX:They were at the supermarket.(main verb)
EX:I am reading Arabic.(helping verb)
EX:He is watching TV.(helping verb)
EX:We are sweeping the floor.(helping verb)
EX:They were playing football.(helping verb)
EX:He was washing the car.(helping verb)

*We negate verb to be by putting "not" to it.And we form questions by inverting the subject and verb to be:
EX:I am not an English teacher.Not(amn't)
EX: Are you an English teacher?
EX:He is not (isn't) ill.
EX:Is he ill?
EX:He was not (wasn't) washing the car.
EX:Was he washing the car?
EX:They were not (weren't) playing football.
EX:Were they playing football?

 

  

2-Verb to "Have"

• Present simple (have-has)
• Past simple (had)
• Past participle (had)

EX:I have a car.(main verb)
-I don't have a car.
-Do you have a car?
EX:He has a pen.(main verb)
-He doesn't have a pen.
-Does he have a pen?
EX:I had a sandwich.(main verb)
-I didn't have a sandwich.
-Did you have a sandwich?
EX:I have bought a car. (helping verb)
-I haven't bought a car.
-Have you bought a car?
EX:I had travelled abroad.(helping verb)
-I hadn't travelled abroad.
-Had you travelled abroad?

*Note:When verb to have is the main verb ,we use "do" as a helping verb in negation and question.We use do or does in present simple and did in past simple.But If it is the helping verb,we use it in negation and question.We only put "not" to it in negation but in question,we invert the subject and the verb to have.

3-Verb to "Do"

• Present simple (do-does)
• Past simple (did)
• Past Participle (done) 

*Verb to "do" is a helping verb for any verb in the present simple even itself.(We use "don't or doesn't" in negation but we use "do or does" before subject in question.

EX:I do my homework every day.(main verb)
-I don't do my homework every day.(don't is a helping verb but do is a main verb).
-Do you do your homework every day?(The first "Do" is a helping verb but the second "do" is a main verb).

EX:The did their homework.(main verb)
-They didn't do their homework.
-Did they do their homework?

EX:She goes to the cinema every Friday.(present simple)
-She doesn't go to the cinema every Friday.
-Does she go to the cinema every Friday? 

EX:We ate fish yesterday.(past simple)
-We didn't eat fish yesterday.
-Did you eat fish yesterday?

*Note:Verb to do must be followed by infinitive.
*Note: Verb to "do" as a helping verb doesn't appear in affirmative sentences but it appears only in negative and question.

*Verb to do appears in affirmative as follows:
1-As a main verb :
EX:I do my homework every day. 

2-To strengthen meaning:( It means actually or already)
EX:I do play chess every day.
EX:He did go home.






 

  

could/should/have+p.p

*Could have +p.p.
-It means that I was able to do something in the past but I didn't do it:(There are a lot of causes that make us forbid doing those things)

EX:I could have driven faster but I drove slowly.It's early.
EX:I could have studied hard but I didn't study.I was very lazy and I don't like learning.
EX:She could have travelled overseas but she preferred staying.She doesn't want to travel.

*Note: Couldn't have +p.p means that you wasn't able to do something either you want to do or not.(It was difficult for any reason).

EX:I couldn't have arrived early to school.The streets were very crowded.Here I wanted to arrive on time but i couldn't.


*Should have +p.p.
-It means that i didn't do something in the past although it was a good idea.(It expresses regretting).

EX:You should have driven slowly.This sentence means that I had an accident because I didn't drive slowly.It was a good idea to drive slowly.Here I regretted not driving slowly.

*Note: Shouldn't have +p.p means that I did something in the past that was a bad idea.

EX:He shouldn't have put salt in the food.That means that the food became too salty because he put salt in the food.His mother put salt before he put.He didn't know that his mother put it.It happened mistakenly but at last regretted doing it.

*Would have+p.p.
-It means that I wanted to do something but I didn't.
EX:I would have gone to the cinema.It means that I didn't go to the cinema because I was very busy.

EX:I would have called you.It means that I didn't call him because the mobile didn't work or I didn't have his number.




 
 










EX:

 

Some and Any

*Some and any go before uncountable nouns or plural countable nouns.
*Some is used in positive sentences but any is used in negative sentences.

EX:There is some water on the table.
EX:There are some apples in the fridge. 
EX:There isn't any water on the table.
EX:There aren't any apples in the fridge.

*We always use any in questions:
EX:Is there any soup in the bowl?
EX:Are there any oranges in the fridge?
EX:Did you buy any vegetables?

*But if we expect the answer is yes,we use some not any:
EX:Did you buy some clothes yesterday?(Here i know that he/she went to buy some clothes) 
 
*We also use some in offers or requests:
EX:Would you like some tea? (offer)
EX:Can you give some water,please? (request) 

*We use any in positive sentences as follows:
EX:Any one can show you the way to the metro.
EX:You may find it at any supermarket. 

*We use any with conditional clauses:
EX:If you saw any one of them,call me.

Suggestion

*There are more than expression to make suggestions:

1-How/What about +v+ing?
EX:How about playing football?
EX:What about going for a walk?

2-Why don't we/you +inf.(For specific suggestion)
EX:Why don't you buy that book?

-We may use "why not' for general suggestion:
EX:Why not spend your holiday in Paris?


3-Let's.
EX:Let's have a snack.

-We use let's not for negative suggestion:
EX:Let's not talk about this.

4-You/we could:
EX:You could sleep early.

5-couldn't or can't you/we+inf.they are strong.
EX:Couldn't you sleep early?
EX:Can't you sleep early?

6-Shall we+inf?
EX:Shall we visit the pyramids tomorrow?

7-I suggest+v+ing.
EX:I suggest playing chess.


*Replies to suggestions: 
1-That's a good idea.
2-Graet idea
3-Why not.
4-I am not very keen on that.
5-I don't think so.
6-I don't feel like it.





-


 

Countable and Uncountable Nouns

*Countable nouns are things which we can count as follows:
-orange       apple       book       door       ball  etc..... . 

-We can add 's' for singular nouns to be a plural noun.
-We can put numbers before countable nouns.
-We can put a/an before singular countable noun.But we can't put a/an before plural nouns.

EX:I ate an apple.
EX:I ate two apples.
EX:I read books. 
EX:I read a books.(false)


*Uncountable nouns are things which we can't count as follows:

-rice        water         juice     sugar       salt        oil      etc... .

-We can't make a plural or change their form.(we can't add 's'.)
-We use a singular verb with them.
-We can't use numbers with uncountable nouns.

EX:I drank tea.Not a tea.
EX:Coffee is my favourite drink.Not coffee are.
EX:He drank two waters.(false)

*Note that we can count uncountable nouns when we put them in containers as follows:

EX:I drank two bottles of water. 
EX:I bought four kilos of meat.
EX:I have three bags of rice.
EX:I bough two cartons of milk.


*There are some nouns that are always uncountable:
-Subjects  :Arabic-English-history-geograpghy-maths.
-Materials :wood-plastic-metal-cloth.
-Liquids    :water-gas-petrol-milk-tea-coffee
-Gases      :air-oxygen-carbon dioxide-nitrogen
-Activities :swimming-football-basketball-tennis 
-Abstract nouns:happiness-love-freedom-peace.

-There are a lot of other nouns which we can't count.You must use a good dictionary to know more .


*There are nouns that can be countable or uncountable.
-hair-paper-light-cheese-coffee-tea ..... etc.

EX:Coffee is my favourite drink.(Unc)
EX:I would like two coffees and two teas.(C)
EX:There is a hair in my food.(C)
EX:She has a long hair.(Unc)
EX:Can you give me some paper?(Unc)
EX:I bought 10 papers(newspapers) yesterday.(C)
EX:This shop has a lot of cheeses.(C)I mean different kinds of cheese.
EX:This room has two lights(bulbs)(C)
EX:The house is full of light.(Unc)

*The nouns that end in (ics) is uncountable:
-gymnastics-athletics-politics....etc.

*Note:You must use a good dictionary to know everything and you must use good books because English is different from other languages.There are some nouns which are countable in English but uncountable in other languages.





  

Pair Nouns and Collective nouns

*Pair Nouns are the things which are made of two parts.The two parts are the same as follows:

glasses     jeans     shorts      scissors      trousers      pyjamas        pants

*A pair noun is always plural so it takes a plural verb:

EX:My jeans are black.Not my jeans is black.

EX:These scissors are sharp.

*A,an and numbers aren't used with pair nouns.But we use a pair of.
EX:I would like to buy a pair of jeans.

*If I want to buy more than one,I use numbers before pairs:
EX:I want to buy three pairs of scissors.
EX:I want to buy three scissors. (incorrect)
EX:My brother bought four pairs of glasses.Not four glasses.

*Note that four glasses is correct when we mean a container of water.
EX:I drank four glasses of water.

*The collective nouns are a group of people ,animals, or things.They take either a singular or a plural verb.They are as follows:

army    club      class       company      family       government        team       staff     etc... .

EX:The government has made a lot of bad decisions.

EX:The government have made a lot of bad decisions.

EX:My family are rich.Or is rich.

EX:This team is co-operative.Or are co-operative.

*There are some nouns which have a plural meaning and take a plural verb:

EX:The police have arrested the thieves.

EX:The cattle are eating on the farm.

EX:People are sad.

Too vs enough

*Too goes before an adjective or adverb,But enough goes after an adjective or adverb:




*Too is used to mean more than sufficient or more /less than necessary.
*enough is used in negative sentences to mean less than sufficient or less than necessary.

EX:Tom's sweater is not big enough.(It means that it doesn't fit me.It is smaller.)
EX:Kevin's sweater is too big.
EX:He drives too quickly.
EX:He doesn't drive slowly enough.

*Enough is used in affirmative to mean sufficient:

 EX:Your jacket is big enough.

*Too many,too much and enough go before a noun:
EX:I bought too many apples.
EX:I drank too much water.
EX:You didn't put enough sugar.
EX:You didn't eat enough bananas. 

*Note that too many is followed by a countable noun, too much is followed by an uncountable noun,and enough is followed by both.

*We can use a prepositional phrase after enough or too:

EX:Your clothes aren't warm enough for winter.
EX:The exam is too difficult for children.
EX:It's too cold to go out.
EX:I didn't bring enough money to buy two CDs.

The Demonstrative Pronouns

*We use (this) and (these) when the things are near.This goes with a singular or uncountable noun.But these goes with a plural noun.

EX:This girl is very beautiful.
EX:This water is too cold to drink it.
EX:These apples are good.

*We use that and those when the things are far from us.Not necessarily very far but what we can't touch it with our fingers.That goes with a singular or uncountable noun.But those goes with a plural noun.

EX:That furniture looks expensive.
EX:That book is about animals.
EX:Those books are mine.

*When we want to refer to a place where we are,we use (this ) not (that):
EX:This is a wonderful garden.(true)
EX:That is a wonderful garden.(false)

*We can use this to introduce people and that to identify people.
EX:John,this is my friend Michael.
EX:That is Andrew over there.

Wishes

                         Wishes

*If we want to talk about wishes in the future,we use:
-I wish (I/we) could+inf.
-I wish (he/she/it/you /they) would+inf.

EX:I wish I could be rich in the future.(I am poor now)
EX:I wish they would stop talking.(The are talking aloud)
EX:I wish we could travel to London.I like London. 

*If we want to talk about wishes in the present,we use:
-I wish+subject+past simple.

EX:I wish I had money now.I don't have money now.
EX:I wish he didn't come with us.He went with them.

EX:I wish It were very cold.It is hot now.

using were instead of was is acceptable with all pronouns but we may use was with its pronouns(I/he /she/it):

EX:I wish It was very cold.

*If we want to talk about wishes in the past,we use:
-I wish+subject+past perfect.
-In this use ,we express regrets about what we did or didn't so we can't change any thing.

EX:I wish I had studied hard.He didn't study so he failed the exam.

EX:I wish I hadn't spent much money last week.I regretted spending a lot of money.

*Note:(If only) is used to talk about regrets like wish either in the present or in the past:

EX:If only I hadn't spent a lot of money.I spent alot.
EX:If only I were free.I am busy. 

Verbs Followed by Gerunds or Infinitives

                      


*These verbs are followed by a gerund or infinitives with no change in meaning:

1-advise.
EX:The teacher advised reading that book.
EX:The teacher advised to read that book.

2-allow.
EX:Some restaurants allow smoking.
EX:Some restaurants allow to smoke.

3-begin(start).
EX:I have begun(started) sleeping.Switch off the lights.
EX:I have begun(started) to sleep.Switch off the lights.

4-cannot bear.
EX:I can't bear seeing you in pain.
EX:I can't bear to see you in pain.

5-continue.
EX:Although she was tired,she continued walking.
EX:Although she was tired,she continued to walk.

6-dislike.
EX:Most people dislike hearing about their faults.
EX:Most people dislike to hear about their faults.

7-forbid.
EX:The law forbids driving over the speed limit.
EX:The law forbids to drive over the speed limit.

8-hate.
EX:I hate talking to bad people.
EX:I hate to talk to bad people.

9-intend.
EX:I intend staying here tonight.
EX:I intend to stay here tonight.

10-like.
EX:None likes being embarrassed in front of others.
EX:None likes to be embarrassed in front of others.

11-love.
EX:I love seeing beautiful girls.
EX:I love to see beautiful girls.

12-need.
EX:This shirt needs ironing.
EX:This shirt needs to be ironed.

13-neglect.
EX:I have neglected doing my job.
EX:I have neglected to do my job.

14-permit.
EX:I don't permit talking without permission.
EX:I don't permit to talk without permission.

15-prefer.
EX:I prefer playing chess.
EX:I prefer to play chess.

*Note:The following verbs are followed by a gerund or infinitives but there is a change in meaning:

1-forget.
EX:I forgot to take the groceries.(I didn't do)
EX:He forgot meeting me at the airport.
(He doesn't remember) 

2-remember.
EX:I remember buying her a present.
(I did in the past)(I have a memory)
EX:I remembered to invite some friends.
(The idea came into my head so I will do in the future)

3-regret.
EX:I regret moving to London.
(I went there but I am not happy)
EX:I regret to tell you the truth.
(I must do unpleasant thing)

4-stop.
EX:I stopped to talk to my teacher.
(I interrupted an action to do another action)
EX:I stopped smoking.(I gave up smoking)
(quit an action or a situation forever)

5-try.
EX:You should try to learn another language.(Encouraging)
EX:I tried driving that car.(I did something for the first time)



 

 

Verbs Followed by Gerunds

                   Verbs Followed by Gerunds
*These verbs are followed by a gerund or gerund phrase:

1-admit.
EX:The thief admitted stealing the money.
2-appreciate.
EX:I appreciated telling the truth.
3-avoid.
EX:I avoid talking to nervous people. 
4-consider.
EX:He is considering moving to America.
5-defer.
EX:We have deffered making a final decision until next week.
6-delay.
EX:The manager delayed the meeting.
7-deny.
EX:Why did you deny going to the club?
8-detest.
EX:I detest waiting for a long time.
9-discuss.
EX:We discussed going to the mountains for the weekend.
10-enjoy.
EX:She enjoys getting up early.
11-escape.
EX:He escaped taking the money.
12-finish.
EX:I finished writing the lesson.
13-forgive.
EX:She forgave my shouting at her last night.
14-imagine.
EX:I can't imagine earning 1000 dollars this year.
15-keep.
EX:Keep working until you finish.
16-mention:
EX:I didn't mention seeing you yesterday.
17-mind.
EX:Do you mind smoking here?
18-miss.
EX:I miss talking to you.
19-postpone.
EX:I postponed traveling.
20-recommend.
EX:I recommend visiting the pyramids in Egypt.
21-suggest.
EX:I suggest playing chess.
22-resist.
EX:I can't resist staying in that hotel.

The Future Perfect and The Future perfect Continuous

*The Future Perfect Tense:
-It is formed with (will have+p.p)
EX:They will have finished. 

*The future perfect expresses an action that will be finished at a specific time or before that time in the future.

EX:I will have finished the exam before twelve o'clock.
EX:By the end of the week, I will have finished building the house.
EX:My father will have bought a car in a week.
EX:Before July,I will have travelled to England.  

*The Future Perfect Continuous: 




-It is formed with will+have been+v+ing.
EX:I will have been studying. 

*The future perfect continuous is used to emphasize the continuous nature of an action.It is used in the same way and with the same expressions as the future perfect.

EX:By tonight, I will have been working for eleven hours without a break.(Future Perfect continuous)
EX:By tonight,I will have worked for eleven hours without a break. (Future Perfect)

Note:Not all verbs can be used in a continuous tense because of the meaning of the verb.Only verbs that show continuous action can be used :      study,work,travel,write,listen,watch,and so on.

EX:I will have been watching the match.(Correct)
EX:I will have been arriving at the airport.(Incorrect)

The Future Continuous Tense

                      The Future Continuous Tense


*The Future Continuous is formed with (will+be+v+ing
or with  going to be+v+ing).

Ex:I will be working tonight.
EX:I am going to be working tonight.
 
*It is used to express an action that will be happening at a given time in the future:

EX:I can't go out tonight.I will be studying for my exam between eight and twelve.
EX:I am going to be studying for my exam between 8 and 7.

*It is also used to express an action that will happen at different times in the future:

EX:In this course,we will have a test after every chapter and I will be giving difficult quizzes from time to time.

*The future continuous expresses an action that will happen at an unknown time in the future.

EX:I will be studying hard soon.
EX:I am going to be studying hard soon.

Will vs Would

                    
*The uses of 'will':
 1- Simple Future:
EX:The meeting will begin at 10 o'clock. 

2-A promise:
 EX:I will buy you a laptop computer.

3-Quick decision:
EX:The weather is very hot so I will open the window.
EX:I am hungry.I will have a snack.

4-An action in the future based on thinking or openion.
EX:I think Liverpool will win the match.I said that because Liverpool won the last two matches.But no proof now.

5-Fact in the future:
EX:Next week,I will be 30.

6-Determination:
EX:At the meeting,we will solve our problems If it takes all night.
 
7-Request:
EX:Will you give me your pen ,please?
*The uses of 'shall':
1-Offer:
EX:Shall I carry these books for you?

2-Simple future with (I/we):
EX:I shall play football now.This use is the same as 'will' here.

3-Suggestion:
EX:Shall we go for a walk?  That's a good idea.

*The uses of 'would': 
1-Polite Request:
EX:Would you close the door ,please?

2-A habit in the past:
Ex:I would eat a lot of sweets when I was young.
-This use is the same as 'used to+inf':
EX:I used to eat a lot of sweets when I was young.
                  
                                         
                                   


















 

Must vs have to

          
         
*The uses of 'Must':
1-Necessity (have/has to):
EX:Students must wear the uniform.
EX:You must obey your father.

2-Orders:
EX:You must take that medicine.(The doctor ordered the patient.)
EX:You must drive on the right.(It is a law)
EX:You must be quiet.(The teacher ordered the students.)

Note:But if we want to repeat orders for others ,we use 'have to' because we are obliged to do something.
(Outer authority) 
EX:We have to drive on the right.(the taxi driver said to his friend because it is a law)
EX:I have to take that medicine.(the patient said to his mother because the doctor ordered him).

Note:There is a difference in meaning between must and have to:
EX:I must see that film.(It expresses my desire to do something)
EX:You have to go to work tonight.(The manager ordered you to go).

Note: IF you want to express necessity in the past,use had to not must and the negative is (didn't have to+inf.).

EX:He had to go to the company yesterday.It means that he already went.
EX:He didn't have to stay at home yesterday.He was busy.

Note:The negation of 'have /has to' is 'don't/doesn't have to' and they mean that there is lack of necessity.But the negation of 'must' is 'mustn't' and it is used for prohibition.They differ in meaning completely.

EX:We don't have to buy vegetables.(We already have) but there isn't a problem if you buy.

EX:You mustn't smoke in hospitals.(It is forbidden)You are not allowed to smoke.

2-Assumption (Deduction).
In this use ,must express a strong deduction that something is true based on available facts,strong evidence.

EX:He must be rich.He has a villa and a Mercedes.
EX:She must live near here.She always walk to school every day.
Note:The negation of must isn't mustn't but is can't.
EX:She can't be poor. 


Note: The deduction in the past isn't 'had to; but is 
'must have +p.p'.And the negation is 'can't have+p.p'.
EX:It must have rained all night .The streets are very wet.
EX:He can't have travelled abroad.I saw him an hour ago.


 

The Uses of Should

                   


The uses of 'should'

1-Obligation:
EX:The teacher should be kind to his students or pupils.But some aren't.
EX:Children shouldn't waste their parent's money.But many do.  

2-Expectation:
-It refers to an action that we are sure will happen because of our knowledge about a situation, a person,and so on.

EX:We should reach the airport in about twenty minutes.The road is not crowded.I repeated this trip many times so I know the distance well.

*An expectation also refers to a condition that we are sure will happen as a result of something:

EX:She should be ill tomorrow.(He ate a lot of eggs and meat.He also drank four glasses of wine 

3-Advice:
When you want to give advice,you express your opinion.The others either agree or not.

EX:You should put litter in a bin.
EX:You should see a doctor.(I see he is very tired all day)
EX:You shouldn't eat too many sweets. (I know they are harmful.)


Note:(Should +have +p.p) is used to express advice,expectation or obligation in the past:

 


EX:You should have studied hard.(Advice).It means that he didn't study and failed the exam.

EX:We should have arrived at the airport twenty minutes ago.
(Expectation).He expected to reach earlier but he reached late.

EX:You should have voted in the election.(Obligation).He didn't vote in the election.



 

May vs Might

                   
 

*The uses of 'May':
1-Permission:
May is more formal than can or could.It indicates respect for others:

EX:May I use your pen? To the police officer.
EX:Could I use your pen ? To a stranger.
EX:Can I use your pen? To a friend.

2-Weak possibility:(Deduction)

EX:It may snow tomorrow.It's weak because I haven't listened to the weather report but the air is cold and the sky looks the way it always looks before it snows.

EX:John may be sick.(He didn't tell me but his eyes  look strange.

*The uses of 'Might' :
1-Weak possibility:
-In this use ,might is the same as 'may' although many grammarians believe that 'might' expresses a weaker possibility than 'may'

EX:It might snow tomorrow.(but probably won't)
EX:John might be sick.(but probably isn't)

Note: May/might +have +p.p. express weak possibility in the past (weak deduction)
EX:He may/might have gone to the club.I went home but he wasn't there .He didn't tell me that he went to the club but I think because he likes going to the club.

Note:If you want to express possibility,put in your mind that 'could' is stronger than may or might.
EX:We could have a vocabulary quiz  tomorrow.We have just finished the lesson,and we usually  have a quiz after each lesson.
EX:We might/may have a vocabulary quiz but I don't think we will.

Can vs Could

                           



*The uses of can:
1- Ability(am,is,are able to):
EX:I can speak three languages fluently.
EX:I am able to speak three languages fluently.

2-Strong possibility:
Here ,can indicates that something is highly capable of happening  as a certain  result of another action.
EX:Don't light a match in this chemical factory!
     The fire can cause an explosion. 

3-Suggestion:
When you don't understand a problem or any thing,I give you an idea or suggestoion as follows:
EX:You can ask Samuel to help you.He is an excellent teacher.

4-Permission:
Can is used to ask for and to give permission:
EX:Can I borrow your camera for one hour?
-Sure.You can.
EX:Can I use your pen,please?
-Yes ,you can.

*The uses of could: 
1-Ability in the past(was.were able to):
-Here ,could is used with a past adverbial phrase or clause:
EX:I could play tennis three years ago.

2- Ability based on certain conditions:
EX:We could leave  now if we want to.
EX:I could be a good chess player if i want to.But i am not interested.

3-Strong Possibility:
EX:Don't drive so fast!We could have an accident.

4-Permission:
-Could is more polite than can:
EX:Could I borrow your camera?
Ex:Could I use your pen,please?

5-Polite Request:
EX:Could you open the door,please?
EX:Could you fetch that chair?

Note: there is a big difference between permission and request.When asking for permission,the speaker wants to do something.But when making a request.the speaker wants someone else to do something.

6-Suggestion:
This use is the same as suggestion with can:
EX:Someone doesn't have any money.I suggest a follows
-You could call your father and ask him for some money.
Or you could borrow some from your friend. 

Note: (Could+have +p.p) is used to express ability that wasn't used in the past .
EX:You could have asked your friends about the appointment.But you didn't.