Hey there! This is TOP episode 108: Have To vs Must. Modals

My name’s Ola and I am an English teacher. My goal is to help you start speaking English with confidence and get rid of speaking barriers. It’s time you started speaking English fearlessly! I’ve been there. I was unable to speak English for many reasons that now I call a language blockade. Today I teach people like you how to speak English with confidence. Go to my website for full transcripts and worksheets to each episode. Happy learning! 

Hello again, thanks for choosing my podcast. Today we’re going to clarify the whole mess around ‘have to’ and ‘must’. Let me say this straight, you overuse the word ‘must’. We have to fix that. 

First I’ll tell you why I think you overuse the word ‘must’ and then we’ll look closer at ‘have to’ and ‘must’. We’ll see the negative forms, past forms and we’ll practice, so please wait for the senetnces to repeat out loud.  

One more thing, please stay till the end because you need to practice speaking and that happens at the end of each episode. Secondly, please subscribe, rate, comment, share, like, do whatever you can to support this podcast. Thank you! Let’s jump right in!

Students love  ‘must’ for the fact that it’s easy. It doesn’t change for each person and it looks similar to the Polish ‘musieć’. ‘Must’ is in fact declining in common usage and we should be mindful of that. It just sounds odd on many occasions. For instance: I must go. Well, sounds odd. I have to go. I have to go sounds more natural. 

Must is very common but as a modal of probability. We talked about this in detail in episode 104. Check it out because it’s important. Using ‘must’ as a modal of probability is popular and we should use it this way. 

‘MUST’ as a modal of obligation is used mostly in writing and formal contexts exclusively.  I’ll come back to this later. However, in modern spoken, colloquial English, people are much more likely to use ‘have to’ for obligation. My recommendation is: avoid using ‘must’. 


Have to mainly expresses general obligations. Strong obligations, possibly from outside. External obligations. Children have to go to school. They are obliged to go there. It is necessary for them to do it. Look at me, I have to wear glasses, or contact lenses. I’m not telling you I like it or I don’t, all you know now is that it’s necessary for me to wear them. That’s it. 

Picture this. You’re having breakfast with your family, your kid doesn’t want to go to kindergarten. He’d rather stay at home but you have work. You start your work in 30 minutes. What do you say to your child? How about this:

I have to go to work. 

I have to be there in 30 minutes.

We have to move faster.

You have to finish your breakfast now.

One more situation to imagine. You’ve just come back home and you’re hungry. You open your cupboards and fridge and see they’re empty. What do you say? You may say:

We have to go shopping, the cupboards are empty. 

It’s necessary for you to go shopping, otherwise you’ll starve. I must tell you, you’re not a very well organised person.  

Negative. Well, the negative form of ‘have to’ is: ‘not have to’. Brilliant. That should be easy, right? Imagine you’re about to visit a museum, and you’re wondering whether the museums are open now and what are the restrictions around them. And you find out that you don’t have to wear a mask while visiting this particular museum. There is no need to wear a mask in this museum. You still can do it, but you’re not obliged to wear it. 

What about the past? What is the past form of ‘have to’? It’s had to. Let’s say you explain to your friend why you couldn’t call him as you had promised. You were busy at work, someone called an urgent meeting, and you couldnt call your friend. What do you say? Something along these lines:

I had to be at the meeting.

I had to participate in the discussion.

I had to organise our schedule. 

It wasn’t your idea, it’s not your personal opinion and it was necessary for you to attend the meeting. That’s it. Someone in authority called a meeting and you had to go. 

Let’s see one question with ‘have to’ and in the past. For instance, your colleague asks you to give him a helping hand. You are surprised, because he had had a lot on her plate and you’re astounded she took on even more duties. You ask her:

Did you have to accept this task?

Did you have to take on this responsibility?


Must also expresses obligation but what’s different is that this time this obligation doesn’t come from the outside. You are internally motivated to do something. You say what you think is necessary. It’s your opinion. Please remember what I said before. Using ‘must’ in this meaning is disappearing from language and this may sound unnatural, ok? Still I want to teach you this because  I just feel like knowledge is the key and if you know this it’s easier for you to understand people. Using ‘must’ for exaggeration, for emphasis is still valid. 

Picture this. You’re sitting in your living room and enjoying the silence. Casually you look through the window, and it’s dirty. What do you say to yourself? Maybe nothing, maybe you don’t even notice. But you might wanna say:

I must clean these windows. 

Nobody wants me to do it, it’s just me. I want to have them cleaned. I must clean those windows. I highlight the fact I see this  as a ‘must’. 

It seems logical that you don’t use ‘must’ for other people, only for yourself. You can’t tell anyone what they think or want. Remember, yet again, ‘must’ is becoming less popular as an obligation, don’t use it with others. Only for recommendations. Yes. There is one good reason for using ‘must’. That is giving strong recommandations. You know your friend will love this tv series on Netflix because he or she is such a great fan of this actress who plays the main role in the show. So, what do you say?

You must watch this series.

You must check this film out.

You must visit that restaurant, you’ll love it. 

Negative. There’s some confusion, because ‘mustn’t’ means there is an obligation for you not to do it. It’s necessary that you don’t do this. Let’s imagine you want to organise a surprise birthday party for you granny and you tell all family members:

You mustn’t tell her what we’re preparing. It’s a secret. You mustn’t tell her. 

As you can see, ‘must’ and ‘have to’ are quite similar, they both express an obligation. But their opposites, ‘mustn’t’ and ‘don’t have to’ are completely different. 

You don’t have to go to the cinema. You can, but you don’t have to.

You mustn’t enter this room. It’s forbidden. Only staff members can go in. 

What about the past tense of ‘must’. As an obligation, ‘must’ doesn’t have its own form, it changes into ‘had to’. 

I had to watch it! 

I had to clean my windows. 

I had to tell you!

I need to tell you one last thing. Something that is counter-intuitive when compared with the rules I’ve just said. Because now you know that ‘must’ is somewhat personal, right. Well, not in written rules.  On the other hand, it makes a lot of sense, because I told you that ‘must’  is declining from use and becomes strictly attached to official warnings, signs, and rules. Must is used more in formal writing, especially in written notices, rules or instructions. Written rules in public places, like airports, use ‘must’. Why? How to memorise this? Think that those written rules need to be concise, short. They need to contain as few letters as possible. They have to be short, clear and simple. The fewer words the better. For example:

You must keep your luggage near you.

You must send this form in 3 days.

And a few example of prohibition:

Students must not leave bicycles here. 

Visitors must not smoke.

Finally, we’ve arrived at the point where you do the talking. Please listen carefully, don’t multitask, just focus. Try to memorise the sentence and repeat out loud. Later, tomorrow perhaps complete the worksheet, ok? Let’s begin:

Children have to go to school.

I have to wear glasses.

We have to move faster.

We have to go shopping, the cupboards are empty. 

You don’t have to wear a mask while visiting this particular museum.

I had to participate in the discussion.

Did you have to take on this responsibility?

I must clean these windows. 

I have to eat something.

You must call her!

You must see it!

You must visit that restaurant, you’ll love it. 

You mustn’t enter this room. It’s forbidden. Only staff members can go in. 

I had to tell you!

Well done! I hope this episode will help you limit your usage of the modal verb ‘must’ or at least narrow it for strong recommendations and official rules. Thank you so much for tuning in. Go to your inbox and grab the worksheet, that’s your homework. If you’re not a member download the worksheet at teacherola.com/108 and become one. It’s free. It’s worth subscribing because in my emails I give you exclusive content and worksheets every week..

Again,thank you for listening, and please share this episode with just one person. Your friend, your family member. Let’s spread the message. No matter what, you can start speaking English fearlessly. There’s zero doubt about it.

I’ll see you here next Wednesday. Come here next week, and see how to expand your comfort zone when it comes to speaking a foreign language. Happy learning. Take care! Stay fearless and say it out loud. Bye!