English uses a single word, but, for every kind of contrast. Spanish splits this work between two conjunctions: pero and sino. Choosing the wrong one is one of the most common mistakes learners make, but the rule is surprisingly clean once you see it.
Pero: adding a contrast
Pero is the default word for but. It introduces a contrast, limitation, or unexpected addition to what came before. The first clause may be affirmative or negative — what matters is that the second clause does not cancel it, it simply qualifies it.
Notice the last example: even though the first clause is negative, pero is still correct because the second clause adds information rather than correcting the first.
Sino: replacing what was denied
Sino means but rather or but instead. It appears only after a negative statement, and its job is to replace the denied element with the correct one. Think of it as not X, but (rather) Y.
No quiero café, sino té.
I don't want coffee, but (rather) tea.
No es mi hermano, sino mi primo.
He isn't my brother, but (rather) my cousin.
No fuimos al cine, sino al teatro.
We didn't go to the movies, but (rather) to the theater.
In every case, the same category (a drink, a relative, a place) is being corrected. The two elements on either side of sino are directly comparable.
The pero vs. sino test
Ask yourself: does the second clause replace or cancel the first?
- Yes, it replaces it → use sino.
- No, it just adds contrast or a qualification → use pero.
No estudia medicina, sino derecho.
She's not studying medicine, but (rather) law.
No estudia medicina, pero sabe mucho de anatomía.
She isn't studying medicine, but she knows a lot about anatomy.
The first sentence corrects the field of study. The second just adds information — she's not a med student, yet she still happens to know anatomy. Both begin with a negative, but only the first meets the replacement test.
Sino que: when the contrast is a full clause
Sino alone connects words and phrases. When the replacement contains a conjugated verb, you need sino que.
No solo llegó tarde, sino que se fue temprano.
Not only did he arrive late, but he also left early.
No lo compró, sino que lo alquiló.
He didn't buy it, he rented it.
The structure no solo... sino (que) también is very common in writing and formal speech to mean not only... but also.
No solo habla español, sino también portugués.
She not only speaks Spanish, but also Portuguese.
Pero and sino at a glance
| Situation | Use | Example |
|---|---|---|
| Contrast after affirmative | pero | Es caro, pero bueno. |
| Contrast after negative (adds info) | pero | No tengo hambre, pero te acompaño. |
| Correction after negative (replaces) | sino | No es azul, sino verde. |
| Correction with full verb clause | sino que | No lo compró, sino que lo alquiló. |
Common mistakes
❌ No es azul, pero verde.
Wrong: after a negative that replaces, use sino, not pero.
✅ No es azul, sino verde.
Correct: sino replaces the denied item with the correct one.
❌ No lo compró, sino alquiló.
Wrong: when the correction is a full verb clause, use sino que.
✅ No lo compró, sino que lo alquiló.
Correct: sino que before a conjugated verb.
❌ Es caro, sino bueno.
Wrong: sino requires a preceding negative — use pero after affirmatives.
✅ Es caro, pero bueno.
Correct: pero adds a contrast after an affirmative statement.
For more on contrast structures with subjunctive, see Concessive: Aunque, A pesar de que. For basic coordination, see Coordinating: Y/E and O/U.
Related Topics
- Coordinating: Y/E and O/UA1 — How to use the basic coordinating conjunctions y and o, and when they change to e and u for pronunciation.
- Ni...Ni (Neither...Nor)A2 — How to use ni and the paired ni...ni construction to negate two or more elements at once.
- Concessive: Aunque, A pesar de queB2 — How to express although, even though, and even if with aunque, a pesar de que, and related conjunctions.