Hello, what is the difference between the verbs acabar and terminar? It seems like they both mean 'to finish', are there any situations in which is using one better than the other?
I would say like 80% of the time they’re interchangeable, except for when they’re not.
I would say the main difference is that terminar is “to finish”, while acabar is more “to bring to an end” or “to end”
Typically when you’re talking about tasks or the progression of something, you use terminar
La película termina con un final de suspenso. = The movie ends on a cliffhanger.
El tren termina en Madrid. = The train (line) ends in Madrid.
Terminé mis deberes. = I finished my chores.
No hemos terminado aún. = We’re not done yet. / We haven’t finished yet.
But like I said, there are times when acabar can be used like terminar.
I would personally use la película termina but you could say la película (se) acaba which is “the movie ends/finishes”
You normally see acabar used more idiomatically, like “to end” or “to end up”
Acabé haciendo la mayoría yo solo. = I ended up doing the majority of it myself.
Acaba durmiendo en el sofá. = He/She ended up sleeping on the couch.
El espejo acaba roto. = The mirror ends up broken.
No quiero acabar en la cárcel. = I don’t want to end up in jail.
And acabar has some other meanings, particularly with different prepositions.
acabar con is more like regular terminar and it means “to bring to an end”, or when used with people it means “to kill” or “to get rid of / to end someone”
Quieren acabar con los deberes en casa. = They want to get rid of homework.
Hablan de acabar con los monopolios. = They talk about doing away with monopolies. / They talk about getting rid of monopolies.
No pienso acabar con mi amistad. = I’m not going to end my friendship.
And with acabar de, this is extremely common for getting the idea of “just” across. This is when you “just” did something, so it’s got a kind of past tense vibe to it:
Acabo de terminar el proyecto. = I just finished the project.
Acabo de decírtelo. = I just told you.
Acabamos de hacer las maletas. = We just packed (our suitcases).
The other common one is acabarse which can be “to end” or “to come to an end”, or in some cases it means “to run out”
Cuando se acabe el tiempo... = Once time runs out...Cuando se nos acabe el tiempo... = Once our time runs out... / Once time runs out on us...
Se acabó. = It’s over. / It’s done. / It’s finished.
Quiero que se acabe la guerra. = I want the war to be over.
Aside from the very specific things that are different, they’re very similar and almost interchangeable to me.