A modal verb is a helper verb that expresses possibility, ability, obligation, or intention. It pairs with a main verb (in its base form) to modify the meaning.
Modal
Meaning
Example
can
ability
I can run fast.
could
past ability / possibility
She could help us.
must
strong obligation
You must leave now.
should
recommendation
He should rest.
will
future intention
They will arrive soon.
would
conditional
I would help if I could.
may
permission / possibility
You may go.
might
weaker possibility
It might rain.
Key properties of English modals
Never conjugated: I can, she can, they can — no -s added
Always followed by the base infinitive (no to): I must go, not I must to go
Examples
Modal
Sentence
can
I can finish this by Friday.
must
You must back up your work.
should
She should call back.
will
He will review the PR.
would
We would go if we had time.
may
You may use the conference room.
might
It might cause a bug.
could
They could ship next week.
have to
I have to submit the report.
need to
She needs to restart the server.
How Spanish handles modals differently
Spanish does not have a separate class of modal verbs — it uses regular verbs that happen to carry modal meaning. These verbs are conjugated normally and are followed by an infinitive.
Structure: conjugated modal verb + infinitive
Quiero comer. = I want to eat. (quiero = I want, comer = to eat)
This is similar to “I want to eat” in English — but in Spanish, this pattern is how all modal-like expressions work.
The 4 core Spanish modal verbs
poder — can / to be able to
Subject
Conjugation
yo
puedo
tú
puedes
él/ella/usted
puede
nosotros
podemos
vosotros
podéis
ellos/ustedes
pueden
Stem-changing: o → ue (except nosotros/vosotros)
Spanish
English
Yo puedo ayudarte.
I can help you.
¿Puedes venir mañana?
Can you come tomorrow?
Ella puede correr rápido.
She can run fast.
Nosotros podemos terminar hoy.
We can finish today.
Ellos no pueden esperar.
They can’t wait.
¿Puede usted firmar aquí?
Can you sign here? (formal)
Yo no puedo hacerlo solo.
I can’t do it alone.
¿Podemos salir ya?
Can we leave now?
Él puede hablar tres idiomas.
He can speak three languages.
Tú puedes lograrlo.
You can achieve it.
querer — to want
Subject
Conjugation
yo
quiero
tú
quieres
él/ella/usted
quiere
nosotros
queremos
vosotros
queréis
ellos/ustedes
quieren
Stem-changing: e → ie (except nosotros/vosotros)
Spanish
English
Yo quiero aprender español.
I want to learn Spanish.
¿Quieres comer algo?
Do you want to eat something?
Ella quiere descansar.
She wants to rest.
Nosotros queremos salir.
We want to go out.
Ellos quieren un café.
They want a coffee.
¿Quiere usted algo más?
Would you like anything else? (formal)
No quiero llegar tarde.
I don’t want to arrive late.
¿Qué quieres hacer?
What do you want to do?
Él quiere comprar una casa.
He wants to buy a house.
Tú quieres hablar con ella.
You want to talk to her.
deber — must / should / to owe
Subject
Conjugation
yo
debo
tú
debes
él/ella/usted
debe
nosotros
debemos
vosotros
debéis
ellos/ustedes
deben
Regular -er verb.
Spanish
English
Yo debo estudiar más.
I must study more.
Tú debes descansar.
You should rest.
Ella debe llamar al doctor.
She should call the doctor.
Nosotros debemos llegar a tiempo.
We must arrive on time.
Ellos deben respetar las reglas.
They must respect the rules.
Usted debe firmar el documento.
You must sign the document.
Yo debo terminar esto hoy.
I have to finish this today.
¿Debo preocuparme?
Should I worry?
Él debe saber la verdad.
He should know the truth.
Debemos hablar de esto.
We need to talk about this.
tener que — to have to (obligation)
tener que is a phrase, not a single verb. Conjugate tener, keep que, then add the infinitive.
Subject
Conjugation
yo
tengo que
tú
tienes que
él/ella/usted
tiene que
nosotros
tenemos que
vosotros
tenéis que
ellos/ustedes
tienen que
Spanish
English
Yo tengo que irme.
I have to leave.
Tú tienes que estudiar.
You have to study.
Ella tiene que trabajar hoy.
She has to work today.
Nosotros tenemos que decidir.
We have to decide.
Ellos tienen que esperar.
They have to wait.
Usted tiene que firmar aquí.
You have to sign here.
¿Tienes que salir ahora?
Do you have to leave now?
Yo tengo que llamar a mi mamá.
I have to call my mom.
Él tiene que comer.
He has to eat.
Tenemos que hablar.
We need to talk.
Strength of obligation: comparison
Spanish
Approximate English
Strength
poder + inf.
can
ability
querer + inf.
want to
desire
deber + inf.
should / must
moral obligation
tener que + inf.
have to
practical obligation
Common mistakes
❌ Using modal + conjugated verb: Puedo hablo → ✅ Puedo hablar — always infinitive after modal
❌ Forgetting stem changes: Yo poder → ✅ Yo puedo (o→ue)
❌ Saying debo de when expressing obligation → ✅ debo alone means “must”; deber de = probability
❌ Separating tener que: Tengo estudiar → ✅ Tengo que estudiar
Summary
Spanish modals are regular verbs conjugated by subject + followed by an infinitive
The 4 core modals: poder (can), querer (want to), deber (should/must), tener que (have to)
Structure: [conjugated modal] + [infinitive]
Strength: poder < querer < deber < tener que
See also:Present Tense — conjugation patterns these verbs follow. See also:Verb Types — -ar/-er/-ir classification.