Demà és la fi del termini.

Catalan often uses the present tense to talk about a future event when the time is already clear from context. Since Demà already tells you the action is in the future, és sounds natural.

So:

• Demà és la fi del termini. = natural
• Demà serà la fi del termini. = also possible, but a bit more explicit or formal

This works much like English Tomorrow is the deadline.

Demà means tomorrow.

The accent mark in demà shows where the stress falls: de-MÀ. In Catalan, written accents often help indicate pronunciation and sometimes distinguish words.

So you should pronounce it roughly like deh-MAH.

És is the third person singular form of ser (to be): he/she/it is.

The accent is important because es without an accent is a different word, often a reflexive or object pronoun.

So:

• és = is
• es = a pronoun, as in reflexive constructions

This is a very common distinction in written Catalan.

Yes. Fi is a feminine noun in Catalan, so it takes la:

• la fi = the end

That may feel a little surprising to an English speaker, because English nouns do not have grammatical gender. In Catalan, though, you simply have to learn the noun together with its gender.

Here, fi means end.

It is not exactly the same as final:

• fi = end as a noun
• final = usually final or ending, depending on context

In this sentence, la fi del termini means the end of the deadline period / the end of the allowed time.

So fi is the right word here.

Not usually. In this kind of sentence, termini means deadline, time limit, or period allowed for something.

So termini is often used for things like:

• application deadlines
• payment deadlines
• legal or administrative time limits

Even though it may look a bit like English term, you should not assume it means the same thing in every context.

Because de + el contracts to del in Catalan.

So:

• de + el = del

That means:

• la fi del termini = the end of the deadline

This is very similar to contractions in other Romance languages and is completely standard.

Catalan uses definite articles more often than English in some expressions, and in this sentence both nouns are specific:

• la fi = a specific end
• el termini = a specific deadline/time limit

So la fi del termini literally works like the end of the deadline.

English may sometimes phrase things more loosely, but in Catalan the articles are normal and necessary here.

Yes, absolutely.

Both are correct:

• Demà és la fi del termini.
• La fi del termini és demà.

The difference is mainly one of emphasis:

• Demà... puts focus on when
• La fi del termini... puts focus on what is happening tomorrow

Catalan allows this kind of flexibility in word order, especially when the meaning is still clear.

It is understandable and correct, but it can sound a little formal or written.

In everyday speech, Catalan speakers might more often say:

• Demà s’acaba el termini. = The deadline ends tomorrow.
• El termini s’acaba demà.
• Demà és l’últim dia del termini. = Tomorrow is the last day of the deadline period.

So your sentence is fine, but there are other very common ways to express the same idea.

A simple approximate pronunciation for an English speaker is:

deh-MAH es luh FEE del tehr-MEE-nee

A few helpful notes:

• Demà is stressed on the last syllable.
• és is a short word, like ess.
• fi sounds like fee.
• termini is stressed on MI: ter-MI-ni.

Exact pronunciation varies somewhat by dialect, but this approximation is a good start.