Why is "Estarán cansados" incorrect?

Question

Last year when I took AP Spanish my teacher said "Estarán cansados" was wrong but failed to explain why. The English sentence she had us translating was "They must be tired." Would it be "Deben de estar cansados?" I don't understand the difference between the two. Please explain the difference between using the future tense and "deber de" to express probability.

Good question. - ian-hill, Dec 11, 2013

Answer 1

Hi,

I am a native Spanish speaker.

The best translation for "They must be tired.", is Ellos deben estar cansados.

So all of you were right!

In this case I assume it is something like..."They ran so far. They must be tired." "Ellos corrieron tan lejos. Ellos deben estar cansados."

Hope this helps!

You can drop off the de "ellos" because "deben" already transmit the idea on its own. But, yes getting a second opinion is a good idea. - yayasuzy1, Dec 11, 2013

Ah that makes sense. Thanks! Still don't understand why you can't use the future tense to express it though. - MiseryRevived, Dec 11, 2013

Te equivocas. "Debe" indica obligación. "Debe de" indica probabilidad, la cual viene siendo este caso - 005faa61, Dec 11, 2013

Tienes razon...necesitas "de" ....."Deben de estar cansados" - yayasuzy1, Dec 11, 2013

Al fin - muchas gracis amigos :) - ian-hill, Dec 11, 2013

Answer 2

After some though I offer this solution:

Se habrán cansado

A native will hopfully come and sort us out.

I hope one of them will Annie - usually they don't and leave us none the wiser. :) - ian-hill, Dec 11, 2013

Answer 3

Misery said: I don't think that's right - deben estar cansados expresses obligation rather than probability.

I agree. Here is the dictionary support.

deber (+ infinitivo)

debo hacerlo -> I have to do it, I must do it
debes dominar tus impulsos -> you must o should control your impulses 

To express possibility the dictionary says:

(expresa posibilidad)

deben de ser las diez -> it must be ten o'clock
no debe de ser muy mayor -> she can't be very old 

The word "must" in English expresses both obligation and possibility.

Gringo, you are right - 005faa61, Dec 11, 2013

Answer 4

Estarán cansados = They will be tired. this is a prediction.

They must be tired = an opinion.

Must is a Modal and I don't know how this usage is expressed in Spanish.

Maybe "Deben estar cansados"

Wait for a native speaker.

ps the date today is 11 12 13 - except in North America.

But the future tense can be used for probability in the present tense in addition to referring to the future - not quite sure I understand your reasoning. The conditional tense can be used to refer to probability in the past. - MiseryRevived, Dec 11, 2013

For example, here is the use of the present tense as probability in examples from a website: ¿Quién será ella? - Who could she be? Estará viajando solo - He must be traveling alone. - MiseryRevived, Dec 11, 2013

I don't think your modal matters, I think thisis what people say. - annierats, Dec 11, 2013

Thanks Misery - question: how does one know when it IS a future usage and not a probabilty? - ian-hill, Dec 11, 2013

Ian - I think it's just context, similar to knowing if a regular ar verb in the nosotros form is in the present or preterite tense since both are the same. - MiseryRevived, Dec 11, 2013

Answer 5

I think Ian is right:

Deben estar cansados. (they ought to be tired)

En la tumba habrá mucho tiempo para descansar. ( I the grave there will be plenty of time to rest)

Hi Annie " ought to be" and "must be" express different things. - ian-hill, Dec 11, 2013

I don't think that's right - deben estar cansados expresses obligation rather than probability. - MiseryRevived, Dec 11, 2013

Answer 6

??

I am taking it in college now so I am by no means fluent, but I don't think so. - MiseryRevived, Dec 11, 2013

Your example looks like a command - You should all be tired. - MiseryRevived, Dec 11, 2013