Connecting simple sentences (and, or, but, because)

Connecting simple sentences with y, o, pero, porque — What, when, and how

Spanish has a small set of very common conjunctions that join words, phrases, and whole sentences. The four basic connectors you learn first are y (and), o (or), pero (but), and porque (because). This guide explains what each word means, when to use it, how to form sentences with it, punctuation notes, common mistakes, and many natural examples (Spanish examples first, then an English translation).

When do I use each conjunction?

y — "and" (addition)

Use y to add items, actions, qualities, or whole sentences. It is a coordinating conjunction: it puts together elements of the same type (nouns with nouns, verbs with verbs, clauses with clauses).

- Nouns: "Compré pan y queso." (I bought bread and cheese.)
- Verbs: "Canto y bailo." (I sing and I dance / I sing and dance.)
- Adjectives: "La casa es grande y luminosa." (The house is big and bright.)
- Clauses: "Llegó tarde y perdió el tren." (He arrived late and missed the train.)
- Shared subject (omit repetition): "María estudia y trabaja." (María studies and works.)

Pronunciation/orthography note (y → e): To avoid the sequence of two similar vowel sounds, y changes to e before words that begin with the vowel sound /i/ (usually spelled i- or hi-). Examples:

- "Ana e Ignacio vienen mañana." (Ana and Ignacio are coming tomorrow.)
- "Padres e hijos deben firmar." (Parents and children must sign.)

A simple way to remember: when the next word begins with the sound "ee...", say "e" instead of "y": "e Ignacio", "e historia".

o — "or" (alternatives)

Use o to present alternatives or choices. The meaning can be exclusive (only one of the options) or inclusive (one, the other, or both), depending on context.

- "¿Quieres té o café?" (Do you want tea or coffee?)
- "Puedes venir hoy o mañana." (You can come today or tomorrow.)

Orthography note (o → u): To avoid two adjacent "o" sounds, o changes to u before words that start with the vowel sound /o/ (usually spelled o- or ho-):

- "No puedo elegir uno u otro." (I can't choose one or the other.)
- "Es uno u ocho?" (Is it one or eight?) — (spoken examples of the rule; in writing numbers are often written with numerals.)

pero — "but" (contrast)

Use pero to contrast two ideas or to qualify what you said in the first part. Pero is a coordinating conjunction that links clauses or phrases of similar grammatical weight.

- "Quería ir, pero estaba enfermo." (I wanted to go, but I was sick.)
- "Hace calor, pero no hay sol." (It's hot, but there's no sun.)

Punctuation note: When pero connects two independent clauses (two simple sentences), Spanish normally uses a comma before pero: "Llegó tarde, pero pidió perdón." For short adjective contrasts inside a clause, the comma is often omitted: "Es inteligente pero humilde." (Both forms may appear; use a comma when the second clause is a full sentence.)

Contrast with sino (common confusion): If the first clause is negative and the second clause corrects or replaces it, use sino (or sino que + verb) rather than pero.

- "No quiero café, sino té." (I don't want coffee, but rather tea.)
- "No vino, sino que llamó." (He didn't come; instead he called.)

porque — "because" (reason/cause)

Porque introduces a subordinate clause that gives a reason or cause. It answers the question "¿por qué...?" (why?).

- "No fui porque estaba enfermo." (I didn't go because I was sick.)
- "Lo digo porque es verdad." (I say it because it's true.)

Punctuation note: Normally you do not put a comma before porque when it introduces a necessary reason: "Se quedó en casa porque llovía." You may use a comma if the causal clause is parenthetical or added as extra information.

Important distinction with similar forms:

- "¿Por qué...?" (two words, with an accent) means "Why...?" — question: "¿Por qué no viniste?" (Why didn't you come?)
- "Porque" (one word) means "because": "No vine porque estaba enfermo." (I didn't come because I was sick.)
- "Porqué" (one word with accent) is a noun meaning "the reason": "No entiendo el porqué de su decisión." (I don't understand the reason for his decision.)
- "Por que" (two words, no accent) appears in some constructions where por + que are separate elements (less common for beginners).

How do I form sentences using these conjunctions?

Connect elements of the same type

Conjunctions should join items of the same grammatical kind. That keeps sentences natural and grammatically correct.

- Noun + noun: "Tomo chocolate y té." (I have chocolate and tea.)
- Verb + verb: "Estudia y trabaja todos los días." (He studies and works every day.)
- Adjective + adjective: "El libro es viejo y valioso." (The book is old and valuable.)
- Clause + clause: "Salió temprano y llegó antes que nadie." (He left early and arrived before anyone else.)

Same subject vs. different subjects

If both verbs share the same subject, you can omit the repeated subject: "Pedro come y duerme" (Pedro eats and sleeps). If the subjects are different, repeat them: "Pedro come y Ana duerme." (Pedro eats and Ana sleeps.)

Verb tenses and agreement

You can join clauses with different tenses: "Llegué y me fui enseguida." (I arrived and left right away.) The conjunction does not force the same tense in both clauses.

Punctuation basics

- Do not put a comma before y or o in simple lists: "María, Juan y Ana llegaron."
- Put a comma before pero when it connects two independent clauses: "Quise ayudar, pero no supe cómo." (This is the usual, clear style.)
- Do not normally put a comma before porque when it introduces a required reason: "No fui porque estaba cansado."

Common mistakes and confusions to avoid

- Mixing y and e: Remember to use e before words beginning with the vowel sound /i/ (i- or hi-): correct: "Ana e Iván", wrong: "Ana y Iván" (the second would be heard as "Ana ee Iván").

- Mixing o and u: Use u before words beginning with the vowel sound /o/ (o- or ho-): correct: "uno u otro", wrong: "uno o otro" (the two o sounds can blend).

- Using pero when you should use sino: If the first clause contains a negation and the second corrects it, use sino or sino que + verb, not pero.
- Wrong: "No quiero té, pero café." (unnatural)
- Right: "No quiero té, sino café." (I don't want tea, but rather coffee.)
- With a full clause: "No vino, sino que llamó." (He didn't come; rather he called.)

- Confusing porque / por qué / porqué / por que: Remember the difference between the question form (por qué), the causal conjunction (porque), the noun (porqué), and the rare preposition+relative (por que).

- Wrong comma placement: Avoid a comma before y or o in a simple list. Put a comma before pero when it links two full clauses.

- Run-on sentences: Resist joining many full sentences with just y — consider punctuation or breaking into shorter sentences if the result is long or confusing.

Comprehensive examples (many natural sentences)

The examples below show how these conjunctions work in a variety of short, natural contexts.

Examples with y (and)

- "Pan y mantequilla." (Bread and butter.)
- "Él corre y ella camina." (He runs and she walks.)
- "La película fue larga y emocionante." (The movie was long and exciting.)
- "Llegué a casa y me dormí." (I got home and fell asleep.)
- "Tengo un perro y dos gatos." (I have one dog and two cats.)
- "Estudia biología e informática." (She studies biology and computer science.) — note the e before informática (starts with i).

Examples with o (or)

- "¿Quieres manzana o naranja?" (Do you want apple or orange?)
- "Puedes llamar o enviar un mensaje." (You can call or send a message.)
- "Debes elegir uno u otro." (You must choose one or the other.)
- "Trabajo hoy u mañana, depende del cliente." (I work today or tomorrow, it depends on the client.)
- "¿Prefieres té u agua?" (Do you prefer tea or water?) — use u before words that start with o.

Examples with pero (but) and with sino (rather/instead)

- "Quería salir, pero empezó a llover." (I wanted to go out, but it started to rain.)
- "Es inteligente, pero perezoso." (He's intelligent but lazy.)
- "No lo hice por miedo, sino por prudencia." (I didn't do it out of fear, but rather out of caution.)
- "No compró el libro, sino que lo pidió prestado." (He didn't buy the book; instead he borrowed it.)

Examples with porque (because) and por qué (why)

- "No fui al cine porque estaba cansado." (I didn't go to the cinema because I was tired.)
- "Te llamé porque necesitaba ayuda." (I called you because I needed help.)
- "¿Por qué llegaste tarde?" — "Porque perdí el tren." (Why did you arrive late? — Because I missed the train.)
- "No entiendo el porqué de su decisión." (I don't understand the reason for his decision.)

Examples that combine connectors

- "Quería ir al concierto, pero no tenía dinero, y además estaba cansado." (I wanted to go to the concert, but I had no money, and besides I was tired.)
- "Puedes estudiar medicina o ingeniería, pero debes escoger ahora." (You can study medicine or engineering, but you must choose now.)
- "No vino porque estaba enfermo, sino que llamó para avisar." (He didn't come because he was sick; instead he called to notify us.)

Quick reference (cheat sheet)

- y = and (joins similar elements). Change to e before words that begin with the vowel sound /i/ (i- or hi-): "Ana e Iván."
- o = or (offers alternatives). Change to u before words that begin with the vowel sound /o/ (o- or ho-): "uno u otro."
- pero = but (contrast). Usually a comma before pero when it connects two full sentences: "Quise ayudar, pero no pude."
- porque = because (gives a reason). No comma before porque in normal causal clauses; it answers "¿por qué...?"

Glossary (short definitions)

- Coordinating conjunction: a word that joins elements of equal grammatical importance (y, o, pero).
- Subordinating conjunction: a word that introduces a dependent clause (porque).
- Independent clause (simple sentence): a clause that can stand alone as a sentence.
- Dependent clause: a clause that cannot stand alone and depends on a main clause (for example, a porque-clause).

If you want, I can give more examples sorted by topic (food, travel, school), or a short printable cheat sheet you can keep for quick review.