Avui m'he aixecat tard perquè ahir no vaig dormir bé.

Because the verb here is aixecar-se, the reflexive form, which means to get up. The m' means myself and comes from em.

So:

• aixecar = to raise, lift
• aixecar-se = to get up, rise

In this sentence, the speaker is getting themself up, so Catalan uses the reflexive pronoun.

It breaks down like this:

• m' = em = myself
• he = I have
• aixecat = gotten up / risen

So literally it is something like I have gotten myself up, but in natural English it means I got up or I’ve gotten up.

Because in Catalan, weak pronouns often contract before a vowel or silent h.

So:

• em + he becomes m'he
• et + has becomes t'has
• es + ha becomes s'ha

This is just normal spelling and pronunciation.

This is a very common tense pattern in Catalan.

• Avui (today) is still seen as part of the current time frame, so Catalan often uses the present perfect: m'he aixecat
• Ahir (yesterday) is a finished past time, so Catalan normally uses the periphrastic past: vaig dormir

So the contrast is very natural:

• Avui m'he aixecat...
• ahir no vaig dormir...

English does not make this distinction in the same way, so this often feels new to learners.

Yes, here vaig dormir means I slept.

This is the Catalan periphrastic past, formed with:

• vaig, vas, va, vam, vau, van
  • infinitive

So:

• vaig dormir = I slept
• vaig menjar = I ate
• vaig arribar = I arrived

Even though vaig comes from anar (to go), in this structure it does not mean movement. It is simply a past tense form.

In Catalan, no usually goes directly before the conjugated verb or auxiliary.

So:

• vaig dormir = I slept
• no vaig dormir = I didn’t sleep

That is the normal position for negation.

Bé means well, and here it is an adverb modifying the verb dormir.

So:

• dormir bé = to sleep well

This is similar to English, where we say sleep well, not sleep good.

Here tard means late, and it functions as an adverb: it tells us how or when the person got up.

So:

• aixecar-se tard = to get up late

It does not change form here.

In this sentence, perquè means because.

So:

• ...perquè ahir no vaig dormir bé = ...because yesterday I didn’t sleep well

This is different from per què, which usually means why or for what.

Compare:

• Perquè no vaig venir? = Why didn’t I come?
• No vaig venir perquè estava malalt. = I didn’t come because I was ill.

The accent and the spacing matter.

Catalan often leaves out subject pronouns when they are not needed, because the verb form already shows who the subject is.

So:

• m'he aixecat already tells you it is I
• vaig dormir also tells you it is I

You could add jo for emphasis, but normally it is omitted.

The dictionary form is aixecar or, in this meaning, aixecar-se.

• aixecar = to raise, lift
• aixecar-se = to get up

Aixecat is the past participle of aixecar.

Yes. Catalan word order is somewhat flexible.

For example, you could also say:

• Perquè ahir no vaig dormir bé, avui m'he aixecat tard.

That still makes sense. But the original version sounds very natural and straightforward: Avui m'he aixecat tard perquè ahir no vaig dormir bé.

In standard Catalan, with compound tenses formed using haver, the past participle is normally invariable.

So both a man and a woman would normally say:

• m'he aixecat

That is the standard form in this sentence.

In most standard pronunciations, the x in aixecat sounds like English sh.

So aixecat is roughly like eye-shuh-KAT or eye-sheh-KAT, depending on accent and dialect.

The stress falls on the last syllable:

• ai-xe-cat

As always, exact pronunciation varies by dialect.