Después de las vacaciones, he vuelto a la universidad.

Después often needs de when it is followed by a noun phrase.

• después de las vacaciones = after the holidays / after the vacation
• después de comer = after eating
• después on its own can mean afterwards / later

So:

• Después de las vacaciones, he vuelto... = After the holidays, I’ve gone back...
• Después, he vuelto... would mean Afterwards, I’ve gone back..., which is a bit different.

In Spanish, vacaciones is normally used in the plural, even when English might say vacation in the singular.

So Spanish says:

• las vacaciones de verano = the summer holidays / summer vacation
• me voy de vacaciones = I’m going on holiday / going on vacation

For a learner, it is best to treat vacaciones as a plural noun in normal usage.

He vuelto is the present perfect: I have returned / I’ve gone back.

In Spain Spanish, the present perfect is very commonly used for actions connected to the present or seen as relevant now. Here, returning to university is presented as a recent event with present relevance: now the speaker is back at university after the holidays.

• he vuelto = I have returned / I’ve gone back
• volví = I returned / I went back

In many parts of Latin America, volví might be more common in a similar context. But in Spain, he vuelto sounds very natural here.

Vuelto is the past participle of volver.

The verb is:

• volver = to return, to go back

Its past participle is irregular:

• not volvido
• but vuelto

So:

• he vuelto = I have returned / I’ve gone back
• había vuelto = I had returned
• ya he vuelto = I’ve already come back

A useful pattern to remember is that several common Spanish verbs have irregular past participles:

• hacer → hecho
• decir → dicho
• ver → visto
• volver → vuelto

With volver meaning to return / go back, Spanish normally uses a before the destination:

• volver a casa = to go back home
• volver al trabajo = to go back to work
• volver a la universidad = to go back to university

So the structure is:

• volver a + place

Be careful: volver a + infinitive means something different:

• volver a estudiar = to study again
• volver a intentarlo = to try again

So:

• he vuelto a la universidad = I’ve gone back to university
• he vuelto a estudiar en la universidad = I’ve started studying at university again / I’ve gone back to studying at university

Literally, universidad means university. But depending on context, an English speaker might naturally translate it as college in some situations.

For example, a British English learner would probably keep university, while an American English learner might sometimes say college more naturally in casual speech.

Still, the Spanish word here is specifically universidad, not a general word for any kind of school.

Yes. Después de las vacaciones is a time expression placed at the beginning of the sentence.

It sets the scene:

• After the holidays, I’ve gone back to university.

The comma is natural because the sentence starts with that introductory phrase. In Spanish, this comma is common and helps readability.

You could also say:

• He vuelto a la universidad después de las vacaciones.

This means essentially the same thing, but the focus feels slightly different because the time phrase comes later.

Yes, you could say:

• Después de las vacaciones, he regresado a la universidad.

It is grammatically correct and means almost the same thing. But he vuelto is usually more common and more natural in everyday speech.

Very roughly:

• volver = the everyday, very common way to say to return / go back
• regresar = also correct, sometimes a bit more formal or simply less common depending on the speaker and region

In Spain, volver is especially frequent in normal conversation.

It can correspond to either come back or go back in English, depending on context.

• he vuelto = I’ve come back / I’ve gone back
• he vuelto a casa = I’ve come back home
• he vuelto a la universidad = I’ve gone back to university

English chooses between come and go based on point of view. Spanish volver does not make that distinction in the same way, so context tells you how to translate it naturally.

Not usually by itself. The most natural reading is simply:

• the holidays ended
• the speaker returned to university

So it sounds like a normal return after a break, such as summer holidays, Christmas, Easter, etc.

If you wanted to make it clearer that someone resumed university after a long absence, Spanish would usually add more context, for example:

• He vuelto a la universidad después de varios años. = I’ve gone back to university after several years.
• He retomado mis estudios. = I’ve resumed my studies.

So in your sentence, the default meaning is just returning after the holidays.