English Grammar: MUST & HAVE TO

Summary

Este video explica la diferencia entre los verbos modales 'must' y 'have to' en inglés, resaltando que en su forma positiva ambos tienen el mismo significado: indican una obligación o regla. También se explora su forma negativa, donde 'must not' señala una prohibición estricta, mientras que 'don't/doesn't have to' indica que algo es opcional. Se usan ejemplos de situaciones cotidianas, como viajar, para ilustrar el uso correcto. El objetivo es aclarar esta confusión común y ayudar a los estudiantes a aplicar estas reglas en la vida real.

Takeaways

• 😀 'Must' y 'have to' en afirmativo tienen el mismo significado y función.
• ✈️ Ejemplos de 'must' y 'have to' incluyen reglas como tener un pasaje y pasaporte para viajar en avión.
• 🧳 Ambos se utilizan para expresar reglas o leyes fuertes, con consecuencias si no se cumplen.
• 📝 En negativo, 'must not' indica una regla estricta, como no fumar en un avión.
• 🤫 'Mustn't' es la forma abreviada de 'must not' y la 't' es silenciosa.
• 🚫 'Must not' es más fuerte y estricto que 'don't have to', que indica que algo es opcional.
• 😕 El negativo de 'have to' ('don’t have to') es confuso y se refiere a elecciones u opiniones, no a leyes.
• 👥 La estructura de 'have to' cambia según el sujeto (has to para él/ella/eso y have to para yo/tú/nosotros/ellos).
• 🛑 'Must' no cambia su forma con el sujeto, lo que lo hace más fácil de usar en algunos casos.
• 🍁 'Don't have to' se usa para expresar opciones, como no tener que comer comida de avión o no tener que probar jarabe de arce.

Q & A

¿Cuál es la diferencia principal entre los verbos modales 'must' y 'have to' en afirmativo?

En afirmativo, 'must' y 'have to' tienen el mismo significado y se usan para expresar reglas o leyes estrictas. Ambos indican obligación o necesidad, sin diferencias significativas en su uso.

¿Cómo se estructura una oración con 'must'?

La estructura de una oración con 'must' es: Sujeto + 'must' + verbo en su forma base. Por ejemplo: 'I must have a ticket to get on that airplane.'

¿Cuál es la diferencia entre 'must not' y 'don’t have to'?

'Must not' indica una prohibición o una regla estricta que no se debe hacer, mientras que 'don’t have to' sugiere que algo es opcional; no es obligatorio hacerlo.

¿Por qué 'must' es más fácil de usar que 'have to' en términos de gramática?

'Must' es más fácil de usar porque no cambia con el sujeto; siempre se usa la misma forma. En cambio, 'have to' cambia a 'has to' con los sujetos 'he', 'she', y 'it', y requiere atención al acuerdo entre sujeto y verbo.

¿Cómo se usan 'must' y 'have to' para dar consejos u opiniones?

'Must' no se usa para dar consejos u opiniones; se utiliza para reglas o leyes. 'Have to' en su forma negativa ('don’t have to') se usa a menudo para expresar que algo es opcional o para dar una opinión o consejo.

¿Cuál es la pronunciación correcta de 'mustn't'?

La pronunciación correcta de 'mustn't' es 'musn't', sin pronunciar la 't'. Es una forma rápida y más natural de decir 'must not'.

¿Por qué es importante entender la función de 'have to' en negativo?

Es importante porque la función de 'have to' en negativo ('don’t have to') indica que algo es opcional y no obligatorio, a diferencia de 'must not', que indica una prohibición.

¿Qué ejemplos se mencionan en el guion para usar 'must' en la vida diaria?

Algunos ejemplos incluyen: 'You must have an airplane ticket to get on the airplane' y 'You must not smoke on the airplane', que muestran reglas o leyes estrictas.

¿Qué consejo se da sobre aprender puntos gramaticales nuevos?

El consejo es siempre cuestionarse la función y utilidad del punto gramatical aprendido en la vida real, preguntándose: '¿Por qué tengo que aprender esto? ¿Cómo puedo usarlo en la vida diaria?'

¿Cómo se diferencia el uso de 'must' y 'have to' al hablar de opciones o elecciones personales?

'Must' se usa para reglas o leyes que se deben seguir, mientras que 'don’t have to' se usa para expresar opciones o elecciones personales, indicando que algo no es obligatorio.

Outlines

00:00

📝 Diferencia entre 'must' y 'have to' en positivo

Este párrafo introduce la importancia de entender los verbos modales 'must' y 'have to' en inglés, explicando que ambos se usan de manera intercambiable en oraciones positivas para describir reglas o leyes estrictas. A través de ejemplos de viaje, se muestra cómo ambos términos indican obligaciones fuertes, como necesitar un boleto de avión o un pasaporte. Se menciona que no hay diferencia real en el uso positivo de estos términos, ya que tienen la misma función, y se resalta la necesidad de cuidado con la concordancia sujeto-verbo cuando se usa 'have to'.

05:03

🛑 Uso negativo de 'must' y 'have to'

Aquí se explora el uso negativo de 'must' y 'have to', destacando que mientras 'must not' indica una prohibición estricta, como no fumar en un avión, 'don’t have to' implica una opción, no una obligación. Se introduce la forma contraída 'mustn't', explicando su pronunciación y su uso en contextos donde se quiere enfatizar una prohibición. Por otro lado, 'don’t have to' indica que algo es opcional, y se ofrecen ejemplos sobre cómo se estructura correctamente este tipo de frases en inglés, aclarando errores comunes en la conjugación.

10:05

🔄 Diferencia entre reglas y opiniones

Este párrafo destaca la diferencia entre reglas estrictas y opiniones personales o consejos. Se utilizan ejemplos para mostrar cómo 'don’t have to' indica elección personal en situaciones cotidianas, como no estar obligado a comprar un regalo o comer comida del avión. Se recalca que aunque algo no sea obligatorio, puede ser recomendado. La idea central es que las reglas como usar el cinturón en un avión son obligatorias, mientras que cosas como probar jarabe de arce en Canadá son opcionales.

Keywords

💡must

El verbo modal 'must' se utiliza para expresar una obligación o una regla estricta. En el video, se explica que 'must' indica algo que debe hacerse, como si fuera una ley. Por ejemplo, 'You must have a ticket to get on that airplane' indica que es obligatorio tener un boleto para subir al avión.

💡have to

'Have to' también expresa una obligación, y en su forma positiva tiene el mismo significado que 'must'. Ambos se usan de manera intercambiable para reglas y leyes, como se menciona en el ejemplo: 'You have to have a passport'. La diferencia está en la estructura gramatical, que varía según el sujeto.

💡must not

'Must not' se utiliza para expresar una prohibición fuerte, indicando algo que no se debe hacer bajo ninguna circunstancia. Un ejemplo en el video es 'You must not smoke on an airplane', que prohíbe fumar en el avión de manera enfática.

💡don't have to

'Don't have to' indica que algo no es obligatorio, a diferencia de 'must not', que expresa una prohibición. Se refiere a una opción o una elección personal. En el video, un ejemplo es 'You don't have to eat that airplane food', donde no es necesario comer la comida del avión, pero es opcional.

💡modal verb

Los verbos modales son auxiliares que expresan necesidad, posibilidad, obligación o consejo. 'Must' y 'have to' son ejemplos de verbos modales que indican obligación. En el video, se explica que 'must' es un verbo modal que no requiere concordancia entre el sujeto y el verbo, a diferencia de 'have to'.

💡subject-verb agreement

La concordancia entre el sujeto y el verbo se refiere a ajustar el verbo según el sujeto de la oración. En el caso de 'have to', se debe usar 'has to' con los sujetos 'he', 'she' y 'it', y 'have to' con 'I', 'we', 'they' y 'you'. Esto es importante para evitar errores gramaticales.

💡negative form

La forma negativa de 'must' y 'have to' cambia el significado de la obligación a la falta de obligación o la prohibición. 'Must not' prohíbe algo, mientras que 'don't have to' indica que algo es opcional. La diferencia es esencial para comprender cuándo algo es una elección o una prohibición.

💡opinion

En el contexto del video, una opinión se expresa con 'don't have to' cuando no es obligatorio hacer algo, pero se sugiere. Por ejemplo, 'You don’t have to buy me a souvenir, but I’d like it' muestra que no es necesario, pero sería un gesto apreciado, expresando una recomendación o consejo.

💡rule

Una regla se refiere a algo que debe seguirse para evitar consecuencias negativas. En el video, se utiliza 'must' y 'have to' para describir reglas estrictas, como 'You must fasten your seatbelt on the airplane', donde no seguir la regla podría tener consecuencias serias.

💡choice

El concepto de elección se refiere a situaciones en las que no se requiere seguir una regla estricta. El video destaca esto al usar 'don't have to', como en 'You don't have to try maple syrup', donde probar jarabe de arce es una opción, no una obligación, reflejando libertad de decisión.

Highlights

Introduction to modal verbs: must and have to and their importance in English grammar.

Must and have to in the positive form have the same meaning: they express strong rules or laws.

Example: To board an airplane, you must have a ticket and a passport. These are non-negotiable rules.

Must is easier to use grammatically because you don't have to worry about subject-verb agreement, unlike have to.

Use must when expressing strict rules, like 'You must not smoke on an airplane.'

Must can be shortened to 'mustn't,' where the 't' is silent.

Must not vs. have to in the negative: 'Must not' is for strict rules, while 'don’t have to' means there is no obligation.

When using have to, you need to be careful with subject-verb agreement. 'He/She/It has to,' but 'I/We/They have to.'

In the negative form, 'doesn't have to' or 'don't have to' is used, maintaining the base verb 'have.'

Doesn't and don't are the only words that change in the negative form of have to.

Don't confuse 'mustn't' with 'doesn't have to.' Mustn't means something is prohibited, while doesn't have to indicates no obligation.

The negative of 'must' is used for very strong rules or laws: 'You must not do this.'

The negative of 'have to' is more about choice: 'You don't have to do this if you don't want to.'

Must often conveys rules, while 'don't have to' expresses someone's opinion or advice.

Conclusion: You must follow rules and laws in strict situations, but in others, it's your choice or option. Like eating airplane food or buying souvenirs – it's your decision!

Transcripts

You must watch this lesson.

You just have to watch this lesson.

It's really important, because it'll help you, and it's confusing in English.

Actually, you don't have to watch this lesson, if you don't want to; it's your choice, but

you've already clicked on it, so let's continue.

I'm going to explain to you two modal verbs that are really confusing in English because

the positive and the negative have different meanings.

Let's start with the first one and the easiest one.

You guys have learned this, I'm sure before, if you studied grammar; or if you haven't

studied grammar, you guys maybe have even heard about this.

It's confusing.

So, what I'm going to teach you today is the difference between the modals: "must" and

"have to".

In the positive, "must" and "have to" have the exact same meaning or the exact same function.

When we use this grammar...

It's grammar.

When we use this grammar, "must" you can think about it like a law or a rule.

Okay?

Something that is very, very, very important; basically, if you don't do it, there will

be bad things that will happen.

So: "must" and "have to" we both use for very strong rules or laws.

So, I want you to think about in your daily life.

Or I'll give you an example of travelling.

So you're going to get on an airplane, so you go to the airport.

What are some things you must have to get on the airplane?

One, you must have-or you have to have-an airplane ticket.

If you don't have an airplane ticket, you're not going to get on that airplane, so you

buy one.

The second thing that you must have-or you have to have-is a passport or some kind of

legal ID; depending on where you are travelling to.

If you're flying internationally to a different country, you definitely have to have-or must

have-a passport.

It's important to have money.

You must have some money, or you have to have some money.

How are you going to live?

How are you...?

You got money.

Okay.

So: "must" and "have to" in the positive form are exactly the same.

I don't care what anyone else has told you before; I don't care what your grammar books

tell you; I don't care what your mom tells you - "must" and "have to" in the positive

are completely equal.

We don't make a difference.

You have to do this or you must do this - the ending is the same.

It's a rule or a law; if you don't do it, there's going to be some problems or you just

won't be accepted.

Can you think of an example in your life that you have rule or a law that you must or have

to do?

Good.

Okay.

Let's look at also the grammar of "have to".

So, "must" is very easy.

It's going to be subject plus "must" plus your base verb.

This is called a modal verb, which is "must".

So, for example: Subject plus "must" plus your base verb.

"I must have a ticket to get on that airplane."

If I don't have a ticket, I can't get on the airplane.

But when we use "have to", we have to be very, very careful or we must be careful with our

subject and our verb agreement.

So, if you have: "He", "She" or "It", we have to say: "has to"; but if you use: "I", "We",

"They", or "You", we have to say or we must say: "have to".

So: "It has to be great.", "We have to go now; it's very important."

So, be careful with our grammar.

The "must" one is easier.

So, if you're deciding on which one you like better - choose "must" because you don't have

to worry about the subject and the verb agreement.

But again, they are not different.

"Must" and "have to" are exactly the same.

The structure is different, but the function or the way we use it is exactly the same.

You choose which one you like the most.

The negative of "must not" is basically telling us a rule in the negative.

For example, you can say: "On the airplane, you must not smoke."

This is a very, very strict law or rule on any airplane in any country of the world that

smoking is prohibited; you can't do it.

If you do it, you will get arrested which means you'll go to jail.

I don't know if you go to jail, but definitely the police will come and you have to pay a

lot of money, so don't do it.

"Must not" we can shorten to: "mustn't".

You mustn't cough during recording because it makes a loud noise.

But when we say this, the "t" is silent; we do not say: "mustn't".

You mustn't pronounce the "t".

You...

When we do this, the "t" is actually silent, we say...

So, we say: "musn't".

So, I can say: "You mustn't smoke on an airplane", or: "You must not smoke on the airplane."

Again, they're the same.

"Mustn't", faster and sounds more natural, but if you want to say: "must not", it sounds

even stronger.

So, if you really want to enforce something or tell someone strongly: "Oh, you must not

do that!

That's bad!

Bad, kitten!"

Is there a kitten?

Where's a kitten?

So: "must not" has the same function as "must".

You're talking about a very strong rule or a very strong law.

Now, this is where we get really confused because the negative of "have to", if you

guys look at this, is: "doesn't have to" with: "He", "She", "It"; and "don't have to" with:

"I", "You", "We", and "They".

So, rule number one: When you have "have to" you have to be careful-or you must be careful-of

the function and of the structure, because the structure is crazy.

If you use negative, we do not change the verb here; we use the auxiliary verb "doesn't"

and "don't", but you keep the verb.

You cannot say; you must not say because it's a rule: "She/He/It doesn't has".

"Doesn't has" is wrong.

You have to use: "doesn't have to".

Okay?

So be very careful with these ones.

"Doesn't" and "don't" are the verbs that are going to change in this grammar.

So confusing; just use this one.

But, again, as I told you, the function is different.

Okay?

Also, remember: Every time you learn new grammar or you learn a new thing in English, please

try and think about: "What's the function?

Why do I have to learn this stupid grammar point?

How can I use this in real life?"

That's what you should always be asking yourself in your classroom, if you're studying by yourself,

if you're speaking, go: "Why?

Why?

Why?

Why?

Why?

Why don't I say: 'She doesn't have to smoke on the airplane'?

Why can't I say that?"

The difference is: This kind of grammar, it's very different from a rule or a law.

This kind of...

Drama.

This kind of grammar, it's basically-and this is fun-it's your choice.

Oh.

It's your option.

If you want to, you can; but you don't have to.

So you have the option to do something.

Oops.

Another thing that you will understand from this is that people will give you their opinion

or their advice; and when we give someone's opinion or advice, they're also going to use

this structure.

So, this one is a very strong rule or law; this one is not a strong rule or a law - this

is your choice or your option, or usually someone's opinion or advice.

So, let's say that you're getting ready to travel and your mom says: "Hey.

You don't have to call me every day", but you should.

Or your friend says: "You know, it's okay; you don't have to buy me a souvenir or a gift

when you go to this new country", but I'd like it a lot.

This is someone's opinion.

You don't have to do it; nobody's holding a gun to your head, saying: "Buy your friend

a gift in this over-priced souvenir store", and your mother...

Mom, thanks for all the advice.

Advice is something that, again, is someone's opinion; it's never a law, unless it's from

your mom.

I'm joking.

Advice and opinion are the same, so it's what people recommend.

But you have to understand that if you don't want to, you don't have to.

When you get on that airplane, there are some rules that you must follow.

You must do up your seatbelt.

Okay?

This is a rule and a law.

You must turn off your cellphone.

But when the food comes down the aisle and you go: "Wow, that smells great", guess what?

You do not have to eat that terrible airplane food.

It's your choice.

If you want to, you can eat that chicken or beef; but she doesn't have to.

She doesn't have to eat it, if she doesn't want to; it's her choice.

When you go to the airport and you're shopping - hey, guess what?

You don't have to buy that bag; it's not important.

But you want to, so that's your choice.

"Oh, I want to buy the bag!"

But you don't have to; it's not a rule.

When you...

If you come to Canada, you don't have to drink maple syrup.

Well, we don't drink it.

You don't have to try maple syrup.

Hey, if you don't want to try maple syrup, that's your choice.

You don't have to do it, but you should; it's fun.

I want you to think about things that you have encountered - maybe at your work or maybe

when you're travelling, or anytime in your life, maybe at your house - things that you

have made a choice to not do; things that your mother tells you that you don't have

to do, but you should.

You don't have to donate money, but you should; it's a great idea.

You must follow me on YouTube.

You must not write bad things.

You have to continue learning English.

Hey, but guess what?

You don't have to, if you don't want to; it's your choice; it's my opinion.

Until then, bye-bye.