por + Infinitive

Reason with Por

Level 4

Use 'por + infinitive' to state the reason for an action. It explains the 'why'. Example: Me premiaron por sacar buenas notas (They rewarded me for getting good grades).

How It Works

The structure por + infinitive is a key way to express the reason, cause, or motive for an action. It answers the question '¿Por qué?' (Why?).

The most important distinction to make is with para + infinitive, which expresses purpose ('in order to').

  • Por + infinitive (Reason/Cause): Identifies the reason or motive.
  • Para + infinitive (Purpose/Goal): Identifies the intended objective.

Compare these two sentences:

  • `Trabajó horas extra por necesitar el dinero.`
    He worked extra hours because of needing the money. (The need is the reason/motive.)
  • `Trabajó horas extra para ganar más dinero.`
    He worked extra hours in order to earn more money. (Earning more is the goal/purpose.)

This structure is very common with verbs of reaction, reward, or punishment:

  • Gracias por ayudarme. (Thanks for helping me.)
  • Me disculpo por llegar tarde. (I'm sorry for arriving late.)
  • Le pagaron por trabajar horas extras. (They paid him for working extra hours.)

For a deeper dive into this distinction, see por vs para.

The contrast is cause versus goal, not a fixed past-versus-future rule. The main event may be future, and the reason can be a continuing state. In 'por haber hecho', the perfect infinitive presents the action as earlier than the reference event; it does not merely mean a more distant past. Other constructions with por + infinitive, such as work remaining to be done, have different meanings.

Examples (5)

  1. Gracias por venir a mi fiesta.

    Thank you for coming to my party.

    Word by Word: Thanks for to come to my party.

    'por venir' explains the reason for the gratitude.

  2. El profesor lo castigó por no prestar atención en clase.

    The teacher punished him for not paying attention in class.

    Word by Word: The teacher him punished for not to pay attention in class.

  3. Recibió un premio por ser el mejor empleado del mes.

    He received an award for being the best employee of the month.

    Word by Word: He received an award for to be the best employee of the month.

  4. Se disculpó por haber hecho tanto ruido anoche.

    She apologized for having made so much noise last night.

    Word by Word: Herself she apologized for to have made so much noise last night.

    'Haber hecho' is a perfect infinitive: it presents the noise-making as earlier than the apology.

  5. Lo criticaron mucho por aceptar esa oferta de trabajo.

    They criticized him a lot for accepting that job offer.

    Word by Word: Him they criticized much for to accept that offer of job.

Common Mistakes

  • Using 'para' instead of 'por' to express a reason or cause.

    Te doy las gracias para invitarme.
    Te doy las gracias por invitarme.

    For gratitude whose reason is the invitation, use por invitarme. Para introduces an intended purpose, a different relationship. The distinction is not simply past versus future; gratitude can also anticipate an action.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

por + InfinitiveLevel 4Reason with Por

Learn This First

To use 'por' with an infinitive to express a reason, you first need to understand the general concept of 'por' as a preposition of cause. Additionally, you must be familiar with how Spanish uses the infinitive form of a verb after prepositions, a concept typically introduced with patterns like 'para + infinitive'.

Words in This Pattern