AmerEngli sh Live Free / Speak Free PRESENTS
May 28, 2015
AmerEnglishLive Free / Speak Free
PRESENTS
Must, Have to, & ShouldPresent Time
must to say that something is essential or necessary
have to to say that something is obligatory
You must study. You have to study.
ExercisesHave to
Should
Need to
Must
Must is a modal auxiliary verb.
Must (subjective obligation)
We often use must to say that something is essential or necessary, for example:
I must go.
subject + must + main verb
Must
Structure of Must
Must is a modal auxiliary verb. It is followed by a main verb. The structure is:
subject + must + main verb
The main verb is the base verb (infinitive without "to").
Look at these examples:
subject auxiliary must main verb
I must go home.
You must visit us.
We must stop now.
NOTE:Like all auxiliary verbs, must CANNOT be followed by to. So, we say:
I must go now. (not *I must to go now.)
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.
Must not, Mustn't (prohibition)
We use must not to say that something is not permitted or allowed, for example:
Passengers must not talk to the driver.
subject + must not + main verb
Structure of Must not
Must is an auxiliary verb. It is followed by a main verb. The structure for must not is:
subject + must not + main verb
The main verb is the base verb (infinitive without "to").
Must not is often contracted to mustn't.NOTE
Look at these examples:
subject auxiliary must + not main verb
I mustn't forget my keys.
You mustn't disturb him.
Students must not be late.
like all auxiliary verbs, must CANNOT be followed by "to". So, we say:
NOTE
You mustn't arrive late. (not You mustn't to arrive late.)
Use of Must not
Must not expresses prohibition - something that is not permitted, not allowed. The prohibition can be subjective (the speaker's opinion) or objective (a real law or rule). Look at these examples:
I mustn't eat so much sugar. (subjective)
You mustn't watch so much television. (subjective)
Students must not leave bicycles here. (objective)
Policemen must not drink on duty. (objective)
We can use must not to talk about the present or the future:
Visitors must not smoke. (present)
I mustn't forget Tara's birthday. (future)
We cannot use must not to talk about the past. We use other structures to talk about the past, for example:
We were not allowed to enter.
I couldn't park outside the shop.
Have to (objective obligation)
We often use have to to say that something is obligatory, for example:
Children have to go to school.
Note that we can use the have to expression in all tenses, for example:I have to, I had to, I have had to, I will have to
NOTE
Structure of Have to
Have to is often grouped with modal auxiliary verbs for convenience, but in fact it is not a modal verb. It is not even an auxiliary verb. In the have to structure, "have" is a main verb. The structure is:
subject + auxiliary verb + have + infinitive (with to)
Look at these examples in the simple tense:
subject auxiliary verbmain
verb haveinfinitive (with to)
+ She has to work.
- I do not have to see the doctor.
? Did you have to go to school?
Use of Have to
In general, have to expresses impersonal obligation. The subject of have to is obliged or forced to act by a separate, external power (for example, the Law or school rules). Have to is objective. Look at these examples:
In France, you have to drive on the right.
In England, most schoolchildren have to wear a uniform.
John has to wear a tie at work.
In each of the above cases, the obligation is not the subject's opinion or idea. The obligation is imposed from outside.
We can use have to in all tenses, and also with modal auxiliaries. We conjugate it just like any other main verb. Here are some examples:
subject auxiliary verb
main verb have
infinitive
past simple I had to work yesterday.
present simple I have to work today.
future simple I will have to work tomorrow.
present continuous
She is having to wait.
present perfect We have had to change the time.
modal (may) They may have to do it again.
must - to have to
Modals - Explanation
We substitute "must" with "to have to".Be careful: The negation of must means not allowed to.
Affirmative sentences
Tense Modal Form
Simple Present
I must play football. I have to play football.
Simple PastDo not use must in the Simple Past.
I had to play football.
will-futureDo not use must in the will-future.
I will have to play football.
NegationsTense Modal Form
Simple Present
1I must not play football.I mustn't play football.
I am not allowed to play football.I'm not allowed to play football.
2I need not play football.I needn't play football. I do not have to play football.
I don't have to play football.3
I do not need to play football.I don't need to play football.
Simple Past
1Do not use must not in the Simple Past.
I was not allowed to play football.I wasn't allowed to play football.
2Do not use need not in the Simple Past.
I did not have to play football.I didn't have to play football.
3I did not need to play football.I didn't need to play football.
will-future
1Do not use must not in the will-future.
I will not be allowed to play football.I won't be allowed to play football.
2Do not use need not in the will-future. I will not have to play football.
I won't have to play football.3
I will not need to play football.I won't need to play football.
Questions
Tense Modal Form
Simple Present
4 Must he play football? Does he have to play football?5 Does he need to play football?
Simple Past4
Do not use must in the Simple Past. Did he have
to play football?5 Did he need to play football?
will-future4
Do not use must in the will-future. Will he have to play
football?5 Will he need to play football?
Should
I like coffee, maybe a little too much. I think I should cut down on coffee. My dad used to say that for a healthy life, you should eat and drink in moderation. In other words, you shouldn’t have too much of any one thing. I should have listened to his advice. What do you think I should do? Do you think I must follow my doctor’s advice?
Today we will look at how to use should Vs must. Do you know how to use these words? Take a look at the paragraph above and then check out today’s lesson:
Should is an auxiliary verb and usually comes before the main verb in the sentence.
Should is used to show obligation. Must is also an auxiliary verb, but it is much stronger than should and is often used for orders.
Compare the following sentences:
My doctor said that I should cut down on coffee. My doctor gave me a strong suggestion.
My doctor said that I must cut down on coffee. My doctor gave me an order.
You shouldn’t use a cell phone on the train. This shows your obligation not to use the phone.
You mustn’t use a cell phone on the train. Maybe there is a regulation prohibiting cell phone use.
You shouldn’t smoke in public places in New York. Not smoking in public is a social obligation
You mustn’t smoke in public places in New York. Smoking in public is prohibited by law.
Should is used to show probability, but must is not used this way:
The meeting should be finished by 2:00. Not, the meeting must be finished…
The flight should arrive on time. Not, the flight must arrive…
Must is used to show something is sure or certain.
The train must be running late. I’m sure the train is running late
You worked until 10 last night! You must be tired. I’m sure you are tired.
Should is used with the past participle (pp) to show what was supposed to happen, but it didn’t:
The meeting should have finished by 2:00. But, the meeting didn’t finish by 2:00.
I should have called before I left the house. But I didn’t call before I left the house.
Must is also used with the past participle (pp) when we want to show certainty about the past
The meeting must have finished by 2:00. I’m sure it finished by 2:00.
I must have left my wallet at home. I’m sure I left my wallet at home.
Need vs Must
Need can be used as an ordinary verb and as a modal verb. The modal verb does not change its tense. It is most common to use the negative.
Modal verbs:
You need not worry, you will be all right.
You need not speak so loudly.
Ordinary Verb:
I need a drink.
So Need usually, please correct me if I am mistaken, talks about whether or not there is a need or reason to do what you are doing. The negative, as said, being common, can give permission not do to something and can say that there is little reason to do like you are doing.
You need not whisper. You need not cut the grass.
However, Must and Need can be similar in the following sentences:
I must meet Susanne.
I need to meet Susanne.
I would put forward, yet to be discussed, that NEED has notion of the speaker deciding, whereas MUST, as well as HAVE TO talk about a, most likely external, obligation.
Well, I should stop for today. You must be tired from studying so hard. I hope you enjoyed today’s lesson…see you next time!
Quiz Time
Directions
Read each sentence carefully, then decide which answer best fills in the sentence. Remember only one answer is correct. Click on your choice.
Are you ready???
No! Yes!
1. Yesterday I ……………………finish my Geography project.
2. She will ……………..wait in line like everyone else.
3. All employees …………………….on time for work.
a. must b. mustn’t c. had to
a. must b. have to c. has to
a. must be b. mustn’t c. have to
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.
a. have to not b. must c. mustn’t
a. have b. must c. mustn’t
a. have to b. had to c. must
7. The doctor …………………get here as soon as he can.
8. Do you …………………………..work next weekend?
9. Bicyclists ……………………….remember to signal when they turn.
a. must
a. have to
a. mustn’t
b. mustn’t c. have to
b. must c. mustn’t
b. must c. has to
10. Angela, you ……………………. leave your clothes all over the floor like this.
a. mustn’t b. must c. have to
How did you do?