In Spanish, “by” changes with the job it’s doing, most often to por for cause/means and para for goal/destination.
You’ve probably hit this snag: you want to say “by” and Spanish asks, “By how? By whom? By when? By which route?” English reuses one small word for a lot of jobs. Spanish splits those jobs across several prepositions, and the choice can flip the meaning.
This article gives you a clear way to pick the right Spanish “by” without guessing. You’ll get fast rules, natural sentence patterns, and the traps that cause the most slip-ups, so your Spanish sounds steady, not translated.
Why “By” Is Tricky In Spanish
In English, “by” can mark an author (“a book by…”). It can set a deadline (“by Friday”). It can show method (“by train”), movement (“walk by the store”), or measurement (“two inches by three”). Spanish still expresses all of those ideas, it just doesn’t pack them into one word.
The good news: most everyday uses fall into two buckets. One bucket is cause, means, route, exchange, or agent—Spanish leans on por there. The other bucket is goal, destination, recipient, or due time—Spanish leans on para there. Sort your sentence into the right bucket and the choice gets easier.
What’s By In Spanish? Meanings You’ll Use Most
Start with this small checklist. Ask which “by” meaning you need, then match it to the Spanish pattern that fits.
By Who Did It Happen
When “by” names the doer in a passive sentence, Spanish uses por.
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La canción fue escrita por Shakira. (The song was written by Shakira.)
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El puente fue construido por ingenieros locales. (The bridge was built by local engineers.)
By Means Or Method
When “by” means “using” a method, tool, or channel, por is common.
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Te mando el archivo por correo. (I’m sending the file by mail/email.)
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Nos hablamos por WhatsApp. (We talk by WhatsApp.)
By Way Of A Route Or Through A Place
When “by” means “through” or “via” a path, Spanish often uses por.
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Pasamos por el centro. (We went by/through downtown.)
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Entró por la ventana. (He came in by the window.)
By A Deadline Or No Later Than
When “by” sets a due time, Spanish usually prefers para.
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Lo necesito para el lunes. (I need it by Monday.)
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La cena está lista para las ocho. (Dinner is ready by eight.)
By As In Next To
When “by” means “beside,” Spanish typically uses junto a or al lado de, not por or para.
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Siéntate junto a mí. (Sit by me.)
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Hay una farmacia al lado del banco. (There’s a pharmacy by the bank.)
By As In Authorship On A Book Or Song
For “a book by X,” Spanish often uses de.
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Una novela de Isabel Allende. (A novel by Isabel Allende.)
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Un disco de Bad Bunny. (An album by Bad Bunny.)
By As In One-By-One Or Step-By-Step
English loves “by” for patterns like “one by one.” Spanish uses set phrases like uno por uno and paso a paso.
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Entraron uno por uno. (They came in one by one.)
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Vamos paso a paso. (Let’s go step by step.)
Por Vs Para: A Simple Two-Question Test
When you’re stuck between por and para, run this quick test.
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Is the sentence pointing to a reason, a route, an exchange, or a method? If yes, start with por.
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Is the sentence pointing to a target, a destination, a recipient, or a due date? If yes, start with para.
This test covers a big chunk of daily Spanish. When you want to verify a tricky use, the Real Academia Española entries for “por” in the DLE and “para” in the DLE show the core senses and common patterns.
By Doing Something: The Pattern English Hides
English often uses “by” plus an -ing form: “By studying, you’ll pass.” Spanish usually expresses that idea with a gerund (estudiando) or with al + infinitive. The choice depends on the feel you want.
Gerund For The Method
If you want the sense of “using this method,” the gerund is a natural fit.
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Aprendes español escuchando todos los días. (You learn Spanish by listening every day.)
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Se ganó la confianza ayudando sin pedir nada. (He earned trust by helping without asking for anything.)
Al + Infinitive For “Upon Doing”
Al + infinitive often carries a “when you do it” or “upon doing it” sense.
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Al estudiar con calma, entiendes más. (By studying calmly, you understand more.)
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Al llegar, llámame. (When you get there, call me.)
Common Uses Of Por With Natural Patterns
Por shows up when something happens due to a reason, moves through space, gets done via a method, or trades at a rate. These patterns will carry you far.
Cause Or Motive
Use por to point to what drove an action.
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Lo hice por ti. (I did it because you were the motive.)
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Cancelaron el viaje por lluvia. (They canceled the trip because of rain.)
Means, Channel, Or Medium
Use por with the way something gets done.
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Te aviso por mensaje. (I’ll let you know by message.)
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Aprendí por mi cuenta. (I learned on my own.)
Movement Through Or Around
Use por for the area you pass through.
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Camina por el parque. (Walk through the park.)
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Vamos por la autopista. (We’re going by the highway.)
Exchange And Rate
Use por for swaps, trades, and “per.”
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Cambié dólares por euros. (I exchanged dollars for euros.)
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Dos cafés por cinco euros. (Two coffees for five euros.)
Agent In Passive Voice
If the sentence is passive and names who did it, por is the usual pick. The RAE overview of the uses of “por” and “para” lays out these roles with clean wording and usage notes.
Table: Fast Matching For English “By” Meanings
This table compresses the most common “by” meanings into a quick match you can reuse while writing or speaking.
| English “By” Meaning | Spanish Pick | Pattern You Can Copy |
|---|---|---|
| Agent in passive | por | Fue hecho por… |
| Cause/motive | por | Por miedo / por ti |
| Method/channel | por | Por correo / por mensaje |
| Route/through | por | Pasar por… |
| Exchange/per | por | X por Y |
| Deadline | para | Para el martes |
| Destination | para | Ir para… |
| Recipient | para | Para ti |
| Beside/next to | junto a | Junto a la puerta |
| Authorship | de | Un libro de… |
Common Uses Of Para With Natural Patterns
Para points toward a destination, a goal, a recipient, or a due time. Think of it as an arrow aimed at an endpoint.
Destination
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Salgo para Madrid mañana. (I’m leaving for Madrid tomorrow.)
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Este tren va para el aeropuerto. (This train goes to the airport.)
Purpose
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Estudio para trabajar en una clínica. (I study to work at a clinic.)
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Compré hielo para la fiesta. (I bought ice for the party.)
Recipient
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Esto es para ti. (This is for you.)
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Un regalo para mi madre. (A gift for my mom.)
Deadline
For “by + time,” para is usually the cleanest option.
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Termina para las seis. (Finish by six.)
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Envíamelo para mañana. (Send it to me by tomorrow.)
How To Choose In Real Sentences
Rules are nice, but your brain usually works from whole sentences. Here’s a fast flow you can run in seconds.
Start With The Verb
Some verbs pull a preposition by habit. “To leave by the door” often turns into salir por la puerta. “To arrive by noon” often turns into llegar para el mediodía. If you want a solid overview of how Spanish prepositional groups work, the RAE page on Spanish prepositions is a reliable reference.
Test The Swap
Try swapping “by” with a clearer English phrase:
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If you can swap to “because of,” “through,” or “via,” you’re in por territory.
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If you can swap to “to,” “toward,” or “no later than,” you’re in para territory.
Watch For Two Meanings
Some English sentences allow two readings. Spanish forces you to pick one, and that’s a gift. Take “I did it for you.” If you mean “intended for you,” you’ll usually say Lo hice para ti. If you mean “because you were the motive,” you’ll usually say Lo hice por ti.
Same English sentence. Two Spanish options. Two different meanings.
Common Mix-Ups And Clean Fixes
These are the spots where learners slip. Fixing them makes your Spanish feel more natural right away.
Mix-Up: Deadline With Por
English says “by Friday,” and learners reach for por. Spanish usually wants para when you’re naming a due time.
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Cleaner: Necesito el informe para el viernes.
Mix-Up: Purpose With Por
If you mean “to” as a goal, use para, not por.
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Salí para comprar pan.
Mix-Up: Motion Past A Place
“I walked by the café” is about passing through that area. Spanish leans to por.
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Pasé por el café.
Mix-Up: “For You” In Two Senses
This one changes tone, so it’s worth getting right.
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Para ti = intended for you, meant for you, a gift for you.
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Por ti = because of you, on your behalf, driven by you.
Table: Quick Fixes For Frequent “By” Sentences
Use this as a mini edit checklist when you’re writing emails, captions, or schoolwork.
| English Sentence With “By” | Spanish Structure | Notes |
|---|---|---|
| Send it by email | Mándalo por correo. | Channel/medium → por |
| Finish it by Monday | Termínalo para el lunes. | Due time → para |
| Walk by the park | Pasa por el parque. | Route/area → por |
| A painting by Goya | Un cuadro de Goya. | Authorship → de |
| Stand by me | Quédate a mi lado. | Beside → al lado de |
| Two by three (size) | Dos por tres. | Measurement “x by y” |
| Learn by listening | Aprender escuchando. | Method → gerund |
A Few Handy Patterns That Don’t Map To Por Or Para
Not every “by” lands on por or para. These patterns show up a lot and are worth memorizing.
By Myself
“By myself” can mean “alone” or “on my own.” Spanish has a few natural picks.
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Estoy solo. (I’m by myself.)
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Lo hice yo solo. (I did it by myself.)
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Lo hice por mi cuenta. (I did it on my own.)
By Chance
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Por casualidad. (By chance.)
By The Way
“By the way” is usually por cierto. It’s a set phrase, so it’s easy to slot in.
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Por cierto, ¿cómo te fue?
By The Time
“By the time” is often para cuando or just cuando, depending on the sentence.
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Para cuando llegues, ya habré salido.
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Cuando llegues, ya habré salido.
A Practical Mini-Drill To Lock It In
Want this to stick? Run a short drill with phrases you already say in English.
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Write five sentences that use “by” in different ways: one deadline, one route, one method, one passive agent, one “beside.”
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Translate them and label each “by” meaning in the margin: deadline, route, method, agent, beside.
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Swap the Spanish preposition and see how the meaning shifts. If it flips the intent, you just learned the boundary.
Do this once or twice and you’ll start choosing por and para on instinct.
Final Checklist Before You Hit Send
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If “by” names a doer, a reason, a route, or a method, try por first.
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If “by” names a destination, a goal, a recipient, or a due time, try para first.
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If “by” means “beside,” reach for junto a or al lado de.
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If “by” marks authorship, de is often the natural fit.
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If “by” means “by doing,” try a gerund or al + infinitive.
Once you get used to asking “what job is ‘by’ doing here?”, Spanish stops feeling picky and starts feeling clear.
References & Sources
- Real Academia Española (RAE).“por | Diccionario de la lengua española.”Lists the main senses of por as a preposition, including agent, route, and time uses.
- Real Academia Española (RAE).“para | Diccionario de la lengua española.”Defines core uses of para, including destination, purpose, and deadlines.
- Real Academia Española (RAE).“Las preposiciones por y para.”Explains frequent values of por and para with usage notes.
- Real Academia Española (RAE).“Las preposiciones.”Overview of how Spanish prepositions form prepositional groups and relate to other words.