¿Cuándo uso "acabar" vs. "terminar"? / When do I use "acabar" vs. "terminar"?

Question

I've seen both "acabar" and "terminar" used to mean "to finish" and "to end", for example:

• "Cuando acabe el café, haga mas." (When you finish the coffee, make more)
• "La musica acabó y me senté en silencio por un momento." (The music ended and I sat in silence for a moment.)
• "La película terminó a las nueve." (The movie ended at 9.)
• "Terminamos el proyecto, y empezamos otro." (We finished the project and started another.)

Are the two words totally interchangable for "to finish / to end", or are there certain situations where it is better to use one than the other? Is one of them more common in everyday speech?

Answer 1

Maybe some sentences sound better with one or another verb, varying with the region, but the two verbs are quite common in speech and writing. You can use any of the two in almost any situation.

Let's see some of the meanings of both words, according to the RAE:

acabar

De cabo.

1. tr. Poner o dar fin a algo. U. t. c. prnl.
2. tr. Apurar, consumir.
3. tr. Poner mucho esmero en la conclusión de una obra.
4. tr. matar.
5. intr. Rematar, terminar, finalizar. La espada acaba en punta.
6. intr. Poner fin, destruir, exterminar, aniquilar. Los disgustos acabaron CON Pedro. Tú acabarás CON mi vida.
7. intr. Haber ocurrido poco antes algo. Acaba DE perder su caudal.
8. intr. No lograr algo. U. con neg. No acaba DE licenciarse.

I have excluded the regionalisms and unused meanings.

terminar

Del lat. termināre.

1. tr. Poner término a algo.
2. tr. acabar (‖ poner esmero en la conclusión de una obra).
3. intr. Dicho de una cosa: cesar (‖ interrumpirse o acabarse). U. t. c. prnl.
4. intr. Aniquilar o destruir enteramente algo o alguien. Hay que terminar CON la injusticia y CON los explotadores.
5. intr. Poner fin a las relaciones, especialmente amorosas, que se mantienen con otra persona. Ha terminado CON su novio.

Now let's see your examples. In all of them you can use any of the two verbs:

• Cuando se acabe/termine el café, haga mas. (1st of acabar, 3rd of terminar.)
• La música acabó/terminó y me senté en silencio por un momento. (1st of acabar, 3rd of terminar.)
• La película acabó/terminó a las nueve. (1st of acabar, 3rd of terminar.)
• Acabamos/terminamos el proyecto, y empezamos otro. (3rd of acabar, 2nd of terminar.)

Now let's match meanings:

• 1st of acabar is the same as 1st of terminar. Seen in previous examples.
• 3rd of acabar is references in 2nd of terminar. Seen in previous examples.
• 3rd of terminar uses the verb acabarse.
• 4th of acabar can be expressed with the 4th of terminar. Example: ¡Acaba/termina con él!
• 5th of acabar uses the verb terminar.
• 6th of acabar is the same as 4th of terminar.
• 8th of acabar can be expressed with the 1st of terminar. Example: No termina de licenciarse.

So we have the 7th meaning of acabar, which cannot be expressed with terminar: termina de perder su caudal does not make sense. And the 5th meaning of terminar cannot be expressed with acabar; as Gorpik said, if you say Pedro acabó con su novia, Pedro is sure to be on the news the next day (4th or 6th meanings of acabar), but you could say Pedro acabó con la relación que mantenía con su novia.

Answer 2

They only scenarios where I can think on a difference is in the relationship context.

-Hace mucho no te veía, ¿cómo está tu novio? -Terminamos (we broke up).

On a slightly different context, a proper translation for "the relationship is over" is "el noviazgo acabó" where the synonym of terminar/acabar, applies again as others have answered.