what is it?
Spanish has two prepositions where English often uses just one: por and para. They are not interchangeable. Por covers cause or reason, exchange or substitution, duration of time, and movement through or along a place. Para marks the recipient of something and a deadline or target point in time. Choosing the wrong one changes the meaning of the sentence entirely, so it is worth learning each use separately.
when to use it
Use por for:
Cause or reason — the motive behind an action. Equivalent to «because of» or «out of».
Exchange or substitution — trading one thing for another. Equivalent to «in exchange for».
Duration — how long something lasts. Equivalent to «for» a period of time.
Movement through or along a place — passing through or moving around a location. Equivalent to «through», «along», or «around».
Use para for:
Recipient — the person or thing something is intended for. Equivalent to «for» in the sense of «intended for».
Deadline or target time — a point in time by which something must be done. Equivalent to «by» or «for» a date.
formation
Both por and para are invariable prepositions — they never change form. They are placed directly before a noun, a pronoun, or an infinitive. The table below summarises each use with its English equivalent and a short example.
| preposition | use | English equivalent | example |
|---|---|---|---|
| por | cause / reason | because of, out of | lo hice por ti |
| por | exchange / substitution | in exchange for | cambié mi coche por uno nuevo |
| por | duration | for (a period) | estudié por dos horas |
| por | movement through a place | through, along, around | caminamos por el parque |
| para | recipient | for (intended for) | este regalo es para ti |
| para | deadline / target time | by, for (a date) | lo necesito para el lunes |
When por or para is followed by the article el, only por contracts: por + el → por el (no contraction). Neither por nor para contract with el the way a does (a + el → al). They remain as written.
examples in context
common pitfalls
Exchange: don't use para. Learners often write «cambié mi coche para uno nuevo» by analogy with English «for». Exchange requires por: cambié mi coche por uno nuevo.
Cause or reason: don't use para. Saying «estoy triste para la noticia» is incorrect. When expressing the cause of a feeling or action, use por: estoy triste por la noticia (I am sad because of the news).
Recipient: don't use por. «Este regalo es por ti» sounds like the gift was made because of you, not intended for you. To mark a recipient, use para: este regalo es para ti.
A quick test: if you can replace the preposition with «because of» or «in exchange for», use por. If you can replace it with «intended for» or «by (a deadline)», use para.