Modal auxalary

           Modal Auxilary

             A modal verb (also 'modal', 'modal auxiliary verb', 'modal auxiliary') is a type of verb that is used to indicate modality – that is, likelihood, ability, permission, and obligation. Examples include the English verbs can/could, may/might, must, will/would, and shall/should.

Examples of modal auxiliary verbs

Before we look at some of the possible meanings of modal auxiliary verbs we need to have some idea of what constitutes a modal in English and where they occur in a sentence. A few more examples should enable us to answer the second of these points fairly quickly and easily - the modals are in bold:

• He should be here by now.
• I could swim quite well when I was younger.
• You mustn't blame yourself for this.
• You might have discussed it with me first.
• You can't be serious!
• Could you open the window please?
• Must you make so much noise?
• She had to take her brother along with her.
• We ought to be going.

It should be clear from these examples that the modal verb occupies the first position in verb phrase, coming before any other auxiliary verb (like have or be) and the main lexical verb.
In questions the modal verb is simply inverted with the subject of the sentence as in examples 6 and 7 and it also carries the negative particle not (3rd and 5th examples).
The subject of the sentence has no effect on the form of the modal since almost in all cases they do not change at all.
So, a modal verb is quite simple as far as its form and position in various types of sentence are concerned; but what exactly are the modal verbs in English? The chart below lists the main modal auxiliaries that you are likely to meet and divides them into two categories pure modals and semi-modals, although in most cases the distinction is merely formal and their meanings are not affected by this division.

Pure modals	Semi-modals
can	ought to
could	has/have (got) to
may	be able to
might
shall
should
will
would
need

need is a special verb since as an auxiliary it is almost always negative and it is also a lexical verb as in sentences like he needs to speak to you now, while it acts as a modal verb in sentences such as you needn't come to work tomorrow where it has the same meaning as don't have to.

The forms of pure modals

The main characteristics of the pure modals are:

• they never change their form irrespective of the subject of the sentence
  e.g. he can swim, not *he cans swim
• following on from the above feature, they do not change to show past tense
  e.g. she had to leave not *she musted leave
• they all carry the negative of the sentence by the addition of not/n't
  e.g. I can't remember not *I don't can remember
• they all form questions by inversion with the subject of the sentence.
  e.g. should I stay?
• they are all followed by the base form of the verb without the addition of to
  e.g. he can swim not *he can to swim

The forms of semi-modals

You will notice that this type of modal is made up of two or more separate words, the last one invariably being to. They are all modal in meaning but not in form as they behave differently in a sentence from the pure modals. It is perhaps best to think of the semi-modals in the form with the to infinitive that is given in the table rather than thinking of them as modals that need to + base form. We need to look at the form of each individual semi-modal separately.

Be able to

We use this semi-modal to express possibility or the ability to do something, but unlike the pure modals, be able to has a full range of tenses and also needs to inflect to show agreement with its subject. For example:

• He is able to offer you the best price possible.
• We were able to get in to see the film.
• They haven't been able to find the missing document.
• So, you aren't able to help.

Notice that the negative is carried either by the be element or the auxiliary verb that is closest to the subject of the sentence. It can also be accompanied by any of the pure modals:

• I will be able to see you after lunch.
• They might not be able to put us up for the night.

Has/have (got) to

This is used to express necessity or obligation to do something and shares some of the features of be able to discussed above. The have element of the form has to change to agree with its subject. Although it is normally used in the present tense, it also has its own past (had to) and can be used with pure modals to show the future or the attitude of the speaker:

• They have to be more punctual.
• He has to take responsibility for the accident.
• I had to help my father repair his car.
• We will have to put this off until tomorrow.
• You shouldn't have to suffer in silence.
• You don't have to come if you don't want to.
• He didn't have to do all the shopping.

From these few examples it should be clear that the negative not again attaches itself to the auxiliary verb (modal or main) that comes immediately after the subject of the sentence.

Ought to

It is usually claimed that the meaning of ought to is the same as should whether it refers to giving advice or making a logical deduction. So, to most native speakers the following sentences with ought to and should feel the same:

• You ought to see a doctor.
• You should see a doctor.
• They ought to have got back home by now.
• They should have got back home by now.

In practice, most speakers tend to prefer should for negatives and questions because the ought to and oughtn't ... to forms can sound rather clumsy and awkward.

• Ought you to be doing that?
• They oughtn't to (ought not to) do that.
• Oughtn't we to leave now?

Meanings of modal verbs

The main function of modal verbs is to allow the speaker or writer to express their opinion of, or their attitude to, a proposition. These attitudes can cover a wide range of possibilities including obligation, asking for and giving permission, disapproval, advising, logical deduction, ability, possibility, necessity, absence of necessity and so on. The problem with each modal verb is that it can have more that one meaning and the interpretation of a particular modal will depend heavily on the context in which it is being used. The following examples should help to illustrate this point.

• It might take more than a week. (possibility)
• You might have told me about it! (showing disapproval)
• He must take his medicine three times a day. (obligation)
• He must be French. (logical deduction)
• I can't lift that suitcase by myself. (ability)
• That can't be the right answer. (logical deduction)
• May I look at the questions now? (asking for permission)
• They say it may snow tomorrow. (possibility)

You probably also noticed from the examples that notions like permission and possibility can be expressed using different modal verbs - this, of course, only serves to complicate matters further since one modal verb can have more that one meaning, and one meaning can be expressed by more than one modal verb. In the space that we have available here it would be impossible to cover all the meanings of each of the modals, so as examples we will look at some of the ways that obligation and logical deduction can be expressed.

Obligation

The two main modals here are must and have to. The difference between them is usually given as follows: must is used to express an internal obligation that is imposed by the speaker, while have to refers to rules and regulations that are imposed from outside the speaker. Again, as with many points of grammar this is only intended as a rough guide.
To express a lack of obligation we cannot just automatically add not to the modal verbs without thinking more carefully about it first. How do you feel about the following sentences for instance?

• He must sing loudly.
• He mustn't sing loudly.

In the first sentence you would probably agree that this is obligation originating from, say, a teacher or someone with authority. The second sentence, however, does not express a lack of obligation but a prohibition to do something. The form that we use to express a lack of obligation could be one of the following:

• He doesn't have to get up early.
• He doesn't need to get up early.

This lack of balance in the use of modals can cause many problems for people who are learning English since it is quite illogical.

Logical deduction

This is another area of modal use that is fraught with difficulties for reasons similar to those just discussed above. Look at the following sentences:
The telephone rings:

• That'll be Frank.
• That must be Frank.
• That should be Frank.
• That could be Frank.
• That might be Frank.
• That may be Frank.

The modal verbs used here have been listed in what many consider to be the order of likelihood of something being true. You may or may not agree with this listing, but it gives you some idea of some of the choices available for drawing logical conclusions from situations. If we look at the negatives of these sentences, however, you can see just how much more complex it can become:

• That won't be Frank.
• That mustn't be Frank.
  (To use musn't in this way as logical deduction is incorrect; we use can't instead.)
• That shouldn't be Frank.
• That couldn't be Frank.
• That mightn't be Frank.

Many of these sentences now denote completely different attitudes to the situation and you may even agree that some of them are either not English or are only marginally acceptable. The sentence which has probably moved furthest from its original intention is the second one (mustn't) which sounds very odd. In fact, the negative of must when we talking about deduction is can't - one more example of how complicated and counter-intuitive the system of English modals can be.

Past time with modal

We noted earlier that the pure modals do not change to show tense. Most of these modals do in fact have either present or future reference, but sometimes we need to refer back to the past. With the semi-modals there is little problem, but how can we do this for pure modal verbs? You may have picked up from some of the previous examples that one way to do this is to insert have immediately after the pure modal. But this is not always the case since can has its own past tense could when it refers to general ability. Some examples should help:

• I can speak German.
• I could speak German when I was seven years old.
• You should see this film.
• You should have seen this film.
• Indonesia must be hot.
• Indonesia must have been hot.
• He could find his wallet.
• He could have found his wallet

exercises

1. There are plenty of tomatoes in the fridge. You..........buy any
2. It's a hospital. You.......smoke
3. He had been working for more than 11 hours. He.......be tired after such hard work. He....... prefer to get some rest. 
4. i......speak Arabic fluently when I was a child and we lived in Morocco. But after we moved back to Canada, I had very little exposure to the language and forgot almost everything I knew as a child. Now, I..........just say a few things in the language. 
5.  The teacher said we........ read this book for our own pleasure as it is optional. But we........read it if we don't want to.

answer

1. There are plenty of tomatoes in the fridge. You needn't  buy any.
2. It's a hospital. You mustn't smoke.
3. He had been working for more than 11 hours. He must be tired after such haed work. He may prefer to get some rest.
4. I could speak Arabic fluently when I was a child and we lived in Morocco. But after we moved back to Canada, I had very little exposure to the language and forgot almost everything I knew as a child. Now, I can just say a few things in the language.
5. The teacher said we can read this book for our own pleasure as it is optional. But we can read it if we don't want to.

 sources
https://en.wikipedia.org/wiki/Modal_verb
https://www.tesol-direct.com/guide-to-english-grammar/modal-auxiliary-verbs 
http://www.myenglishpages.com/site_php_files/grammar-exercise-modals.php

Conditional Sentence If Clause

Conditional Sentence If Clause

Conditional Sentences are also known as Conditional Clauses or If Clauses. They are used to express that the action in the main clause (without if) can only take place if a certain condition (in the clause with if) is fulfilled. There are three types of Conditional Sentences.

Conditional Sentence Type 1

It is possible and also very likely that the condition will be fulfilled.

Form: if + Simple Present, will-Future

Example: If I find her address, I’ll send her an invitation.

Form

if + Simple Present, will-Future

• Example: If I find her address, I will send her an invitation.

The main clause can also be at the beginning of the sentence. In this case, don't use a comma.

• Example: I will send her an invitation if I find her address.

Note: Main clause and / or if clause might be negative. See Simple Present und will-Future on how to form negative sentences.

• Example: If I don’t see him this afternoon, I will phone him in the evening.

Use

Conditional Sentences Type I refer to the future. An action in the future will only happen if a certain condition is fulfilled by that time. We don't know for sure whether the condition actually will be fulfilled or not, but the conditions seems rather realistic – so we think it is likely to happen.

Example: 

1. If I find her address, I’ll send her an invitation.

I want to send an invitation to a friend. I just have to find her address. I am quite sure, however, that I will find it.

Example:

  

      2. If John has the money, he will buy a Ferrari.

I know John very well and I know that he earns a lot of money and that he loves Ferraris. So I think it is very likely that sooner or later he will have the money to buy a Ferrari.

Conditional Sentences Type I (likely)

Condition refers to:	IF Clause		Main Clause
future action	Simple Present	If the book is interesting, …	Future I	…I will buy it.
			Imperative	…buy it.
			Modal Auxiliary	…you can buy it.
action going on now	Present Progressive	If he is snoring, …	Future I	…I will wake him up.
			Imperative	…wake him up.
			Modal Auxiliary	…you can wake him up.
finished action	Present Perfect	If he has moved into his new flat, …	Future I	…we will visit him.
			Imperative	…visit him.
			Modal Auxiliary	…we can visit him.
improbable action	should + Infinitive	If she should win this race, …	Future I	…I will congratulate her.
			Imperative	…congratulate her.
			Modal Auxiliary	…we can congratulate her.
present facts	Simple Present	If he gets what he wants, …	Simple Present	…he is very nice.

Conditional Sentence Type 2

Form

if + Simple Past, main clause with Conditional I (= would + Infinitive)

• Example: If I found her address, I would send her an invitation.

The main clause can also be at the beginning of the sentence. In this case, don't use a comma.

• Example: I would send her an invitation if I found her address.

Note: Main clause and / or if clause might be negative.

Example: If I had a lot of money, I wouldn’t stay here.

Were instead of Was

In IF Clauses Type II, we usually use ‚were‘ – even if the pronoun is I, he, she or it –.

Example: If I were you, I would not do this.

Use

Conditional Sentences Type II refer to situations in the present. An action could happen if the present situation were different. I don't really expect the situation to change, however. I just imagine „what would happen if …“

• Example: If I found her address, I would send her an invitation.

I would like to send an invitation to a friend. I have looked everywhere for her address, but I cannot find it. So now I think it is rather unlikely that I will eventually find her address.

• Example: If John had the money, he would buy a Ferrari.

I know John very well and I know that he doesn't have much money, but he loves Ferraris. He would like to own a Ferrari (in his dreams). But I think it is very unlikely that he will have the money to buy one in the near future.

Conditional Sentences Type II (unlikely)

Condition refers to:	IF Clause		Main Clause
present / future event	Simple Past	If I had a lot of money, …	Conditional I	…I would travel around the world.
consequence in the past	Simple Past	If I knew him, …	Conditional II	…I would have said hello.

Conditional Sentences Type II (impossible)

Condition refers to: IF Clause Main Clause present Past Perfect If I had known it, … Conditional I …I would not be here now. past Past Perfect If he had learned for the test, … Conditional II …he would not have failed it.  Conditional Sentence Type 3 It is impossible that the condition will be fulfilled because it refers to the past. Form: if + Past Perfect, Conditional II (= would + have + Past Participle) Example: If I had found her address, I would have sent her an invitation. Form if + Past Perfect, main clause with Conditional II Example: If I had found her address, I would have sent her an invitation. The main clause can also be at the beginning of the sentence. In this case, don't use a comma. Example: I would have sent her an invitation if I had found her address. Note: Main clause and / or if clause might be negative. Example: If I hadn’t studied, I wouldn’t have passed my exams. Use Conditional Sentences Type III refer to situations in the past. An action could have happened in the past if a certain condition had been fulfilled. Things were different then, however. We just imagine, what would have happened if the situation had been fulfilled. Example: If I had found her address, I would have sent her an invitation. Sometime in the past, I wanted to send an invitation to a friend. I didn't find her address, however. So in the end I didn't send her an invitation. Example: If John had had the money, he would have bought a Ferrari. I knew John very well and I know that he never had much money, but he loved Ferraris. He would have loved to own a Ferrari, but he never had the money to buy one.  Exercises 1.      If Caroline and Sue........the salad, phil.......the house 2.      If Sue ..............the onions for the salad, caroline............the mushrooms 3.      Jane...........the sitting room if aaron and tim..............the furniture 4.      If Bob.............up the kitchen, Anita............the toilet 5.      Elaina.............the drinks if somebody.........her carry the bottles 6.      If alan and rebecca..........the food, mary and conor...............the sandwiches 7.      If Bob.............after the barbecue, sue.............the guest in 8.      Frank............The Dj if the others.........along their CDs. 9.      Alan.............The drinks if jane..............him some of her cocktail recipes 10.  If they all...........their best, the party.........Great Answer If Caroline and Sue prepare the salad, Phil will decorate the house. If Sue cuts the onions for the salad, Caroline will peel the mushrooms. Jane will hoover the sitting room if Aaron and Tim move the furniture. If Bob tidies up the kitchen, Anita will clean the toilet. Elaine will buy the drinks if somebody helps her carry the bottles. If Alan and Rebecca organise the food, Mary and Conor will make the sandwiches. If Bob looks after the barbecue, Sue will let the guests in. Frank will play the DJ if the others bring along their CDs. Alan will mix the drinks if Jane gives him some of her cocktail recipes. If they all do their best, the party will be great. https://www.ego4u.com/en/cram-up/grammar/conditional-sentences/type-1/exercises https://www.ego4u.com/en/cram-up/grammar/conditional-sentences