Must may and might compared

Use of Must

In general, must expresses personal obligation. Must expresses what the speaker thinks is necessary. Must is subjective. Look at these examples:

• I must stop smoking.
• You must visit us soon.
• He must work harder.

In each of the above cases, the "obligation" is the opinion or idea of the person speaking. In fact, it is not a real obligation. It is not imposed from outside.

It is sometimes possible to use must for real obligation, for example a rule or a law. But generally we use have to for this.

We can use must to talk about the present or the future. Look at these examples:

• I must go now. (present)
• I must call my mother tomorrow. (future)

We cannot use must to talk about the past. We use have to to talk about the past.[12] 
 

    1.4. May, Might and Must compared using

    One of the meanings of may and might is to be allowed to.  
e.g. The members of the organization agree that I may join it. 
      The members of the organization agreed that I might join it.[11] 
The auxiliary must is a stronger form of may and might. One of the meanings of must is to be obliged to or to have to. 
e.g. You must provide proper identification in order to cash a check. 
      They must work harder if they are to succeed. 
 
It should be noted that the meaning of must not is to be obliged not to. 
e.g. You must not leave. 
      He must not speak.

    The first example has the meaning, You must stay. The second example has the meaning, He must be silent.

    In order to express the idea of not being obliged to do something, an expression such as not to be obliged to or not to have to is generally used.  
e.g. You do not have to leave. 
      He is not obliged to speak.[11]

    The first example has the meaning, You may stay, if you wish. The second example has the meaning, He may be silent, if he wishes. 
Like could and would, might can be used in polite requests and suggestions. The auxiliaries could, would and might can be used to express differing degrees of politeness:

Degree of Politeness	Auxiliary
somewhat polite	could
quite polite	would
very polite	might

    Thus, might expresses the highest degree of politeness. 
e.g. Might I observe what you are doing? 
      Might I offer some advice?[11] 
May, might and must are also used to express differing degrees of probability:

Degree of Probability	Auxiliary
somewhat probable	may, might
highly probable	must

    For instance, may and might are often used in the Simple conjugation to express the idea that an event is somewhat probable. 
e.g. You might be right. 
      It may snow later this afternoon.

    Similarly, must can be used in the Simple conjugation to express the idea that an event is highly probable. 
e.g. He must be mistaken. 
In the following examples, the Perfect conjugations with may, might and must are used to express differing degrees of probability relating to past events. 
      Rupert might have taken the money, but it seems unlikely. 
      It is possible he may have called while we were out. 
      It must have rained last night, because the streets are wet. [11] 

    The following is the table of the main using of the may, might and must.

May	May I have another piece of toast, please?  Iraq may become a democratic society some day.	Politely asking permission  Future possibility
Might	If we go to the park we might see our friends	Future possibility
Must	We must wear a safety belt when we are in the car.    We mustn’t go in there because the sign says “Do Not Enter.”	Necessity or obligation (self-imposed)  Prohibition

[13] 

1.5. How to Write Sentences Using Modal Verbs:

Subject + modal + second verb. (Never add -s, -es, -ed, or -ing to the second verb.)

• I + can + sleeping six hours tonight.
• I + couldn't + worked last night.

permission	Can/May I have another piece of cake, Dad? (request)  You can/may leave at 5:30 if you like.  Might I have a word with you? (BrI) (formal request)	Can is commonly used to ask for or give permission. May is more formal. Could and might are used to ask for (not to give) permission.
possibility	She may/might (not) go to Paris tomorrow  They may/might (not) be meeting her.  Joe may have/might have missed the train.	Could suggests that something is less likely than may or might.
certainty	Joe must be at least 45. I'm sure he's at least 45.  He must have graduated years ago. I'm sure he graduated years ago.  We can't have been at college together. I'm sure we weren't at college together.	Must have is the past form of must when it is used to express certainty. Must and must have express stronger certainty than will and will have.
obligation, requirement	You must finish this job by tomorrow.  I must phone my parents tonight.  He had to finish the job by the next day.  You must not smoke in the cinema. (= it is forbidden)	Had to is the past form of must when it is used to express obligation. Must not is used to show that there is an obligation not to do something. The contracted forms mustn't are common in British English but rarely used in American English.

[From Longman's Dictionary of Contemporary English, New Edition, 1991, pp 669-671. ]

      From this table we can see that there are a lot of deferent meanings that can be expressed by modals. Some meanings could be emphasized by different modals but even taking this into consideration we must take care about tune of the conversation, vertical or horizontal dialog even mood of a person

      So, the first task before saying something is to think about meaning of the saying.

      To find a clear line between uses of different modals is not an easy task. The main thing to chose the right modal is to understand the meaning of the utterance.

      So, speaking generally, both may and serve to express supposition but their use is not parallel. May denotes supposition implying uncertainty whereas the supposition expressed by must implies strong probability.

      May and must are used to express prohibition in negative sentences. But may is seldom found in negative answers to question with may asking for permission we generally find must not or cannot. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

    Chapter II: Practical comparison of modal verbs must, may and might

EXERCISES

  For better understanding the using of the may, might and must one should made the exercises. The examples of them see below. 

1. Change the following affirmative statements into negative questions. Do not use contractions in this exercise. [9]

For example: 
      He must be at work now. 
      Must he not be at work now? 
      They might call us later. 
      Might they not call us later? 
1. You might be wearing a warm hat. 
2. He might have decided to stay at home. 
3. They might have forgotten the message. 
4. She must see you again to decide this problem. 
5. They may enjoy riding on the ferry. 
6. He may decide to go camping. 
7. They must have been playing football yesterday. 
8. We might visit our friends. 
9. She must have wanted to join us. 
10. He must be getting more sleep. 

2. For each of the following sentences, change the verb in the main clause from the Simple Present to the Simple Past; and change the modal auxiliary from the present to the past. [9]

For example: 
      He asks if he may do it. 
      He asked if he might do it. 
      Do you think she must manage it? 
      Did you think she had to manage it? 

1.She says he may go. 
2. The boss says we must finish on time. 
3. They know we may help them. 
4. He says he must leave. 
5. We believe she may be there. 
6. Do you hope they will reply soon? 
7. Does he not realize we may meet him there? 
8. You think we can reach our destination by nightfall. 
9. I suppose he must be at home. 
10. I predict I must be succeed. 

3. Literary Translation [7]

    Я дивилась на незнайомця. Не  може бути, щоб ми коли-небудь зустрічались. Його можна було б прийняти за іспанця, якщо б не блідість обличчя. Невже він брат Сібілли? Він, звичайно, не може належати ло цієї родини.

    - Ви могли б люб’язно провести  мене до кімнати?- посміхаючись сказав він. Я зуміла зобразити ввічливу посмішку.

    - Звичайно. Можу я Вам допомогти  відчути себе як вдома?

    - Дякую, але не можете. Адже вам  не можна розмовляти з чужими. Я прекрасно обійдусь сам.

 
4. Fill in the blanks, indicating whether each of the following sentences is somewhat polite (S), quite polite (Q), or very polite (V). Notice the indirect phrasing of the most polite requests and suggestions. [9]

For example: 
      Could you pass the butter? S 
      Would you please pass the butter? Q 
      Might I trouble you to pass the butter? V 
 
1. Could you help me? ___  
2. Would you like some help? ___  
3. Might I be of assistance? ___  
4. You could come with us. ___  
5. You might wish to accompany us. ___  
6. Would you like to come with us? ___  
7. Might I trouble you for two pounds of fish? ___  
8. I would like to buy two pounds of fish, please. ___  
9. Could you give me two pounds of fish? ___  
10. Could I have your opinion on this? ___  
11. Would you please tell me what you think? ___  
12. Might I know your feelings on the matter? ___  
 
5. Complete each of the following sentences with the auxiliary may, might or must. Use may or might when the event described seems somewhat probable, and use must when the event described seems very probable. [10]

For example: 
      You ___ be right; we shall have to wait and see. 
      You may be right; we shall have to wait and see. or You might be right; we shall have to wait and see. 
 
      That ____ be our landlord; I would recognize him anywhere. 
      That must be our landlord; I would recognize him anywhere. 
 
1. Although it _________ be true, it seems unlikely. 
2. That _________ have been the number 10 bus, because no other bus runs on this street. 
3. We __________ have to wait a long time for a bus, because they do not run very frequently. 
4. That ________ be the right answer; there is no other possibility. 
5. Tell me your problem; I _________ be able to help you. 
6. It _________ have been he who answered the phone, because no one else was at home. 
7. Since we have never been to this store before, we _________ have difficulty finding what we want. 
8. You _________ be pleased that you are doing so well in your new job. 
9. I _________ go downtown tomorrow; it depends on the weather. 
10. Although he is a very careful worker, it is possible that he _________ have made a mistake. 

6. Fill in the spaces with the right modal verbs.  
Example: I ________ speak English very fluently. (key = can) [19]

1.	You   run faster if you weren't so lazy.
2.	You   leave the class before 1 o'clock.
3.	You   behave well in front of guests. Stop being silly.
4.	You look tired. You   have some sleep.
5.	You failed in your final test. You   have studied harder.
6.	I borrow your pen?
7.	We   watch TV so much.
8.	We   not climb those mountains when we were kids.
9.	The project   finish in two years time.
10.	Stop smoking! You really   not smoke.
11.	Sami   lift that heavy table. He is too weak.
12.	Muneera   come to the party, but nobody is sure.
13.	Laila   not swim when she was one year old.
14.	It's too cold. I   close the window.
15.	It   rain in the desert sometimes, but you can't depend on it.
16.	If I had enough money, I   travel with my friends but now I can't.
17.	I   to study well for the exam.
18.	I wish I   buy a new car but i do not have any money.
19.	I have no time. I   leave now. My parents are waiting for me.
20.	He   be friendly, but he is usually unfriendly.

     
7. Literary translation [7]

    Я, мабуть, запізнився хвилин на десять. Підходячи до дверей кабінету м-ра Моргана, я хвилювався, чи зможе він мене прийняти, і тому не помітив записки: „Не заважати!” Я майже вже підняв руку, щоб постукати, але почув чиїсь голоси.

• Може, він зовсім не прийде, - сказав хтось.
• Він не може не прийти. Це обов’язково, і він знає про це,- відповів інший. (Мова, мабуть, йшла про мене.)- Мабуть, просто затримався десь.

    Я знав одного із співрозмовників. Це був  мій вітчим. Але що б це він  міг робити так рано у кабінеті приїжджого? Мабуть, вони зустрічатись раніше. Але де? Я наважився постукати. Відійшовши тихенько від дверей, я пішов навмисне так лунко, щоб вони могли почути мої кроки, і постукав.

    - Увійдіть!- Мр.Морган сидів один  у кабінеті, заваленому купою  паперів. – Вам, мабуть, не казали, синку, що слід приходити вчасно,- пробуркотів він, не підводячи голови.

    Я оглянув кімнату. Куди ж міг подітися мій вітчим? У кабінеті навіть заховатися не було де. 

    8.Use must, might, may, could or can't plus the correct form of the verb. [21]

1. Where is David? He___(be) at school. Classes begin at 8.
2. She ___(think) that it is a good idea. It's crazy!
3. I'm absolutley sure!. They____(arrive) yesterday, I saw their ticket.
4. Courses____(begin) the fifth of September.
5. Are you joking! David____(go) to Paris last week. He doesn't have enough money.
6. They ________(live) in New York, but I'm not sure.
7. The concert _____(be) wonderful last night. Fiore is a great conductor.

 

    9.

Have to, Must, Must not Quiz [24]

1. Yesterday I___ finish my Geography project.
2. She ___ wait in line like everyone else.
3. All employees___ wait in line like everyone else.
4. We___ forget to take the chicken out of the freezer.
5. If you are under 13 you___ to get your parents' permission.
6. Your daughter may___ try on a few different sizes.
7. The doctor___ get here as soon as he can.
8. Do you___ work next weekend?
9. Bicyclists___ remember to signal when they turn.
10. Angela, you___ leave your clothes all over the floor like this.

 

10. Read this with a dictionary; see how must reflects the hearer’s wishes.[7]

(In a dream? Mrs.Ogmore-Pritchard is talking to her two dead husbands, Mr.Ogmore and Mr.Pritchard.)