deben
/DEH-ben/
they must
Ellos deben (They must/should) finish the task.
deben(Verb)
they must
?strong obligation
,they have to
?necessity
they should
?advice, recommendation
,they ought to
?moral obligation
📝 In Action
Ellos deben terminar la tarea antes de salir.
A2They must finish the homework before going out.
Ustedes deben respetar las reglas del juego.
A2You (all) must respect the rules of the game.
Los doctores dicen que todos deben comer más verduras.
B1Doctors say that everyone should eat more vegetables.
💡 Grammar Points
Obligation: deber + [base verb]
To say someone 'must' or 'should' do something, you use 'deber' followed by the simple, unchanged form of the next verb. For example, 'Ellos deben estudiar' (They must study).
'deben' vs. 'tienen que'
'Deben' often suggests a moral duty or strong advice ('They should be honest'). 'Tienen que' usually implies an external rule or necessity ('They have to wear a uniform'). In many cases, they can be used interchangeably.
❌ Common Pitfalls
Adding an extra word
Mistake: "Ellos deben a estudiar."
Correction: Ellos deben estudiar. The verb 'deber' connects directly to the next verb without needing a little word like 'a' or 'de' in between when talking about obligation.
⭐ Usage Tips
Softening your advice
While 'deben' means 'they should,' it can sound quite strong. To give friendlier, softer advice to a group, you can use the conditional form: 'Ustedes deberían descansar más' (You all should rest more).
Ellos deben (They must be/probably are) asleep.
deben(Verb)
they must be
?supposition, logical conclusion
they probably are
?high probability
📝 In Action
No contestan el teléfono. Deben estar ocupados.
B1They're not answering the phone. They must be busy.
Las luces están apagadas, así que deben de haber salido ya.
B1The lights are off, so they must have already left.
Marta y Luis son muy altos. Sus padres deben ser altos también.
B2Marta and Luis are very tall. Their parents must be tall too.
💡 Grammar Points
Guessing: 'deber (de) + [base verb]'
To make a strong guess, you can use 'deben' just like you do for obligation. Sometimes you'll see 'deben de', which also signals a guess. Today, many speakers drop the 'de' and just use 'deben'.
❌ Common Pitfalls
Confusing Obligation and Guessing
Mistake: "To say 'They have to be at the office,' someone might say, 'Deben estar en la oficina' (which sounds like a guess: 'They must be at the office')."
Correction: For a clear obligation, use 'Tienen que estar en la oficina.' Use 'deben' when the context makes it clear you're guessing, not stating a rule.
⭐ Usage Tips
Let Context Be Your Guide
Don't worry about mixing up the 'must do' and 'must be' meanings. The situation almost always makes it clear. If someone points to a dark house and says 'Deben estar durmiendo,' you'll know it's a guess, not a command for them to sleep!
Ellos deben (They owe) money or a favor.
📝 In Action
Ellos me deben cincuenta euros de la cena de anoche.
A2They owe me fifty euros from last night's dinner.
Si no pagan hoy, todavía deben el alquiler del mes pasado.
B1If they don't pay today, they still owe last month's rent.
Ustedes me deben una disculpa por llegar tan tarde.
B1You (all) owe me an apology for arriving so late.
💡 Grammar Points
Owing Something: 'deber + [thing owed]'
When 'deber' means 'to owe', the thing that is owed comes directly after the verb. For example, 'Ellos deben el dinero' (They owe the money).
❌ Common Pitfalls
Adding 'por'
Mistake: "Ellos deben por la comida."
Correction: Ellos deben la comida. In English we say 'owe *for* something,' but in Spanish you just say you 'owe the thing' directly.
⭐ Usage Tips
It's Not Just About Money
You can use 'deben' to say people owe things that aren't money, like favors ('un favor'), respect ('respeto'), or an explanation ('una explicación').
🔄 Conjugations
indicative
present
preterite
imperfect
subjunctive
present
imperfect
✏️ Quick Practice
💡 Quick Quiz: deben
Question 1 of 2
In the sentence 'Las calles están mojadas; deben haber llovido,' what does 'deben' mean?
📚 More Resources
Frequently Asked Questions
What is the difference between 'deben' and 'tienen que'?
'Deben' is often about a moral obligation, a recommendation, or a duty ('They should be more careful'). 'Tienen que' is usually for a stronger, more unavoidable necessity, often from an external rule ('They have to wear a helmet'). In many everyday situations, you can use either, but 'tienen que' sounds a bit stronger.
Is 'deben de' different from 'deben'?
Traditionally, yes. 'Deben de' was used only for making a guess ('They must be tired'). 'Deben' was for obligation ('They must work'). However, in modern Spanish, many people use 'deben' for both meanings and the 'de' is often dropped. So, you'll hear both, but context will always tell you which meaning is intended.