Nowadays, when learning a language everyone wants to be able to speak fluently. Oftentimes we concentrate on speaking first to make sure we can deliver the message. So where does the grammar come into the picture?

Whether you realize it or not, you use grammar every time you say or write something in a foreign language. So even though people can understand you, wouldn’t it be even better to be accurate and grammatically correct?

Yes, even in this era of Google translate, mastering grammar is still highly relevant and you will find a lot of people that will assess your ability to speak or write by your use of grammar.

In LIA, we care about the future of our students, so we decided to create a series of articles where we can enrich our students and provide a little extra for those who want to go a bit further and have some fun with grammar and other language components.


In this article, we will discuss the modal auxiliary verbs SHOULD and MUST.  Let’s start by studying them one by one.


SHOULD is used when we want to give advice or a suggestion to someone. We can also use SHOULD in negative form (SHOULDN’T) when we advise someone not to do something bad. In questions, SHOULD is usually used in order to ask for a suggestion or agreement.


  • You look pale. I think you should go to a doctor.
  • She shouldn’t study until late at night. It is not good for her.
  • Should we finish this meeting now?


MUST has a meaning similar to SHOULD, except that it’s a much stronger word. It is used when we want to emphasize the necessity of doing (or not doing) something. MUST represents more of an obligation, while SHOULD represents a recommendation. We use MUST in the negative form (MUSN’T) to tell someone that he/she is not allowed to do a certain action or activity.


  • Everyone must stay at home during this Covid-19 pandemic.
  • He mustn’t smoke. This is an air-conditioned room.
  • When must we submit this homework?


Both SHOULD and MUST take the base form of verbs. So when we want to make a sentence using SHOULD or MUST, we can construct it in the following way:

Subject + Modal Aux (SHOULD/MUST) + V1 + Complement

I should sleep earlier tonight. I need to wake up early tomorrow.


To make a negative sentence, add NOT after the modals.

Subject + Modal Aux (SHOULD/MUST) + NOT + V1 + Complement

You must not (mustn’t) tell her about this. She’d be so upset.


And to make a question, put the subject of the sentence after the modals:

Modal Aux (SHOULD/MUST) + Subject + V1 + Complement ?

Should we go now? It’s already late in the evening.

Question Word + Modal Aux (SHOULD/MUST) + Subject + V1 + Complement ?

Where must he send this package to? Can you give him an address?


We hope you find this article useful. See you in the next lessons!

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See if you still remember the formula above, and rearrange these words into the correct orders. Have fun!

1 / 8

should – smoking – give – I – up.

2 / 8

I – should – or – her – tell – not?

3 / 8

too – work – hard  – shouldn’t – Jeff.

4 / 8

to – what – improve – should – I – English – my – do?

5 / 8

turn – mustn’t – loud – too – the – music – you.

6 / 8

must – homework – do – you – your.

7 / 8

go – doctor – to – a – see – now – must – he?

8 / 8

box – where – must – this – put – I?

Your score is

The average score is 44%


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