Spanish Modal Verbs: Poder, Tener que, Deber (Ability, Obligation, and Probability)

¡Hola a todos! As you build your Spanish skills, you'll quickly want to express concepts like ability ("I can swim"), obligation ("You have to study"), or possibility ("It should be easy"). This is where **modal verbs** (los verbos modales) come in handy.

Modal verbs modify the meaning of another verb, adding layers of possibility, necessity, advice, or probability. They are typically followed by an infinitive. Understanding and using the most common Spanish modal verbs – poder, tener que, and deber – is a key step for A2 and B1 level learners.

Think of modal verbs as expressing *how* or *why* the main action is done (can it be done? must it be done? should it be done?).

Index: Essential Modal Verbs

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Poder (To Be Able To / Can)

The verb poder is used to express ability, possibility, or permission. It is an irregular verb, especially in the present tense.

Conjugation (Present Tense): Poder

  • Yo puedo
  • Tú puedes
  • Él / Ella / Usted puede
  • Nosotros/as podemos
  • Vosotros/as podéis
  • Ellos / Ellas / Ustedes pueden

Notice the stem change from `o` to `ue` in most forms, except for `nosotros/as` and `vosotros/as`. You will also learn its conjugations in other tenses like the Pretérito Indefinido (`pude`, `pudiste`, etc.).

Usage: Poder + Infinitive

When used as a modal verb, poder is always followed by the infinitive of the main verb.

Examples (Ability):

  • Yo puedo hablar español. (I can speak Spanish / I am able to speak Spanish.)
  • ¿Tú puedes venir mañana? (Can you come tomorrow?)
  • Mi hermano puede nadar muy bien. (My brother can swim very well.)
  • Nosotros podemos ayudarte. (We can help you.)

Examples (Possibility):

  • Puede llover esta tarde. (It may/might rain this afternoon / It can rain this afternoon - implying possibility.)
  • El tren puede llegar tarde. (The train may/might arrive late.)
  • No puedo salir; tengo mucho trabajo. (I can't go out; I have a lot of work - indicating impossibility due to circumstances.)

Examples (Permission - often a question):

  • ¿Puedo usar tu teléfono? (Can I use your phone? / May I use your phone?)
  • Sí, puedes sentarte aquí. (Yes, you can sit here / you may sit here.)
  • No, no puedes entrar. (No, you cannot enter.)

Tener que (To Have To)

Tener que expresses obligation or necessity. It's a strong way to say that something *must* be done. It is formed using the verb tener followed by que and the infinitive.

Conjugation (Present Tense): Tener

First, you need the present conjugations of the irregular verb tener (to have):

  • Yo tengo
  • Tú tienes
  • Él / Ella / Usted tiene
  • Nosotros/as tenemos
  • Vosotros/as tenéis
  • Ellos / Ellas / Ustedes tienen

Usage: Tener que + Infinitive

Just add the fixed phrase que and the infinitive of the main verb after the conjugated form of tener.

Examples (Obligation/Necessity):

  • Yo tengo que estudiar para el examen. (I have to study for the exam.)
  • ¿Tú tienes que trabajar hoy? (Do you have to work today?)
  • Ella tiene que ir al médico. (She has to go to the doctor.)
  • Nosotros tenemos que comprar comida. (We have to buy food.)
  • Ellos tienen que levantarse temprano. (They have to get up early - note reflexive verb follows.)

Tener que expresses an external obligation or a strong necessity (e.g., dictated by rules, circumstances, or another person). It's generally stronger than deber.

Deber (To Ought To / Should / Must)

The verb deber is used to express obligation (often softer than tener que), recommendations, or probability/likelihood.

Conjugation (Present Tense): Deber

Deber is a regular -ER verb in the present tense:

  • Yo debo
  • Tú debes
  • Él / Ella / Usted debe
  • Nosotros/as debemos
  • Vosotros/as debéis
  • Ellos / Ellas / Ustedes deben

Usage: Deber + Infinitive OR Deber de + Infinitive

Like poder, deber is usually followed by the infinitive of the main verb. The inclusion of de changes the meaning slightly (see below).

Examples (Obligation/Recommendation - Deber + Infinitive):

  • Yo debo estudiar más. (I should/ought to study more - a self-recommendation or mild obligation.)
  • Tú debes comer más sano. (You should eat healthier - advice/recommendation.)
  • Ellos deben respetar las reglas. (They must/should respect the rules - a rule or strong recommendation.)

Examples (Probability/Likelihood - Deber de + Infinitive):

When deber is followed by de and an infinitive, it expresses probability or supposition, similar to "must be," "should be," or "probably is/does".

  • Él no responde. Debe de estar ocupado. (He's not answering. He must be busy / He is probably busy.)
  • Son las ocho. El museo debe de abrir ahora. (It's eight o'clock. The museum should be opening now / is probably opening now.)
  • No ha comido nada. Debe de tener mucha hambre. (He/She hasn't eaten anything. He/She must be very hungry / probably is very hungry.)

While the distinction between deber + infinitive and deber de + infinitive for obligation vs. probability exists, in practice, native speakers sometimes use deber + infinitive for probability too. However, learning the distinction is helpful.

Comparing Poder, Tener que, and Deber

Let's summarize the core meanings:

  • Poder: Ability or possibility ("can do").
  • Tener que: Strong obligation or necessity ("have to do").
  • Deber: Softer obligation/recommendation ("should do") OR probability ("must be doing").

Comparing Obligation:

  • Tengo que estudiar. (I have to study - strong necessity/external pressure.)
  • Debo estudiar. (I should/ought to study - a recommendation, perhaps internal.)

Comparing Possibility/Probability:

  • Puede estar en casa. (He/She can/may be at home - possibility.)
  • Debe de estar en casa. (He/She must be at home / is probably at home - probability based on evidence/reasoning.)

Practice Tips: Using Modals Confidently

Integrating these three modal verbs will significantly improve your ability to express a wider range of ideas. Here’s how to practice:

  • Describe Your Abilities: Talk about what you puedo do (abilities) and what you no puedo do (inabilities). "Puedo cocinar, pero no puedo cantar."
  • List Your Obligations: Make a list of things you tienes que do each day or week. "Tengo que ir al trabajo. Tengo que limpiar la casa."
  • Give Recommendations: Offer advice to yourself or others using deber. "Debes dormir más. Debemos comer mejor."
  • Make Predictions: Use deber de for things you think are likely. "El tráfico debe de ser malo ahora."
  • Listen Actively: Pay attention to native speakers using these verbs. Note which tense they use and the context.
  • Combine with Other Structures: Use modal verbs before infinitives that include object pronouns or reflexive pronouns (e.g., "Puedo verlo", "Debo lavarme").

Start by focusing on the present tense, as it's the most common. As you learn other tenses, you'll conjugate the modal verb (poder, tener, deber) in that tense, and the main verb will remain in the infinitive.

Ready to Express Ability, Obligation, and Probability?

Poder, tener que, and deber are fundamental modal verbs that are key to more complex and natural Spanish communication. Mastering their meanings, conjugations, and usage with infinitives opens up many possibilities for expressing yourself.

Sprachlingua's online Spanish courses provide structured lessons that cover these modal verbs in detail, with clear explanations, targeted practice exercises, and valuable conversational opportunities with experienced teachers. We help you build the confidence to use these powerful verbs correctly and fluently.

Ready to add ability, obligation, and probability to your Spanish vocabulary?

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