Modal verb + infinitive
English modals are frozen (I can, she can). Spanish modals conjugate like any other verb: puedo, puede, pueden. The second verb stays in the infinitive and follows directly, with no to and no preposition: Quiero comer.
Stem change in poder and querer
poder and querer change their stem vowel, as tener does: o becomes ue, e becomes ie. Only nosotros and vosotros keep the original vowel.
poder and querer in the present
| Person | poder | querer |
|---|---|---|
| yo | puedo | quiero |
| tú | puedes | quieres |
| él/ella/usted | puede | quiere |
| nosotros/as | podemos | queremos |
| vosotros/as | podéis | queréis |
| ellos/ellas/ustedes | pueden | quieren |
poder: can, may
poder covers can (ability) and may (permission). Questions with poder are the usual way to ask permission or a favour.
Puedo nadar muy bien.
I can swim very well.
¿Puedo entrar?
May I come in?
¿Puedes abrir la ventana?
Can you open the window?
querer: to want
querer + infinitive means to want, with no to in Spanish. With a person as its object it means to love: Te quiero.
Quiero aprender español.
I want to learn Spanish.
¿Quieres un café?
Would you like a coffee?
Te quiero mucho.
I love you very much.
tener que: to have to
tener que + infinitive says what you concretely have to do, like have to. tener is conjugated (tengo, tienes, tiene ...); the que always stays.
Tengo que irme ahora.
I have to go now.
Tenemos que estudiar para el examen.
We have to study for the exam.
deber: should
deber is regular like comer (debo, debes ...). It says what is right or sensible and is softer than tener que, like should next to have to.
Debes llegar a tiempo.
You should arrive on time.
Debo estudiar más.
I should study more.
Negation
no goes directly in front of the modal. Can't / may not is no poder, don't have to is no tener que.
No puedo venir hoy.
I can't come today.
No puedes fumar aquí.
You can't smoke here.
No tienes que trabajar.
You don't have to work.
