UNIT 5 LESSON B

MODALS

We use have to or has to when say what's necessary.
It's necessary that doctors take care of patients.
Doctors have to take care of patients.

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​Have to / Has to

Universidad Politécnica Salesiana del Ecuador

It’s necessary
The plumber has to repair pipes.
.

It’s necessary
The electricians have to repair the electrical
equipment

We use don't have to or doesn't have to when say what is not necessary.
It's not necessary to use candles at the university.
We don't have to use candles at the university because there's an electricity plant.

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Don't have to

Universidad Politécnica Salesiana del Ecuador

It’s not necessary
The plumber doesn’t have to check electrical equipment.

It’s not necessary
The electricians don’t have to repair
water pipes.

Multiple Choice

It's necessary for accountants to keep financial accounts.

Accountants _________ keep finalcial accounts

• have to

• has to

• don't have to

• doesn't have to

Multiple Choice

It's necessary for a plumber to check water pipes.

A plumber _________ check water pipes.

• have to

• has to

• don't have to

• doesn't have to

Multiple Choice

It's not necessary for a scientist to buy the material for the experiments.

A scientist _________ buy the material for the experiments

• have to

• has to

• don't have to

• doesn't have to

Multiple Choice

It's not necessary for bankers to repair the ATM.

Bankers _________ repair the ATM.

• have to

• has to

• don't have to

• doesn't have to

We use must when say what's necessary.
It's necessary that doctors take care of patients.
Doctors must take care of patients.
NOTE: Must and have to, have similar meanings they are used when something is necessary.

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Must

Must is often used in written rules.

​Doctors must have a university degree.

Must

Must is often used in written rules.

Students must have 70 points to approve.

We use mustn't/ can't when something isn't allowed or prohibited.
It's not allowed for doctors to reveal information of patients.
Doctors mustn't/ can't reveal information of patient

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Mustn't / can't

Universidad Politécnica Salesiana del Ecuador

It’s not allowed (not posible)
The electricians can’t check problems without disconnecting
electricity.
The electricians mustn’t check problems without disconnecting
electricity.

.

The plumber can’t spy people’s house.
The plumber mustn’t spy people’s house.

It’s not allowed (not posible)

We use can when something is allowed or permitted.
It's allowed for doctors to check patients.
Doctors can check patients.

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Can

Universidad Politécnica Salesiana del Ecuador

It’s allowed (permitted)
The electricians can work at home.

It’s allowed (permitted)
The plumber can use his own equipment.

Multiple Choice

It’s not necessary

The scientist ___________ (study) marketing.

• doesn't have to study
• can study

• mustn't study

• don't have to study

Multiple Choice

It's not allowed for lawyers to reveal their clients' secrets.

Lawyers ________(reveal) their clients' secrets.

• can reveal

• has to reveal

• must reveal

• can't reveal

Multiple Choice

It’s not necessary

The lawyer  ___________________(wear) a uniform

• don't have to wear

• mustn't wear

• haven't wear

• doesn't have to wear

Multiple Choice

It’s not allowed (not posible)

The hairdresser__________ (steal) his/ her clients.

• must steal

• have to steal

• can not steal

• has to steal

Multiple Choice

It’s allowed (permitted)

The accountant __________(work) for more than one company.

• can work
• can not work

• mustn't work

• has to work