Acesta este ultimul mesaj.

Acesta is a demonstrative pronoun meaning this one / this.

In Romanian, there is an important difference:

• acest mesaj = this message
  
  • here acest is a demonstrative adjective/determiner placed before a noun
• acesta = this one / this
  
  • here acesta replaces the noun, so it is a pronoun

In Acesta este ultimul mesaj, the word acesta stands on its own, so Romanian uses the pronoun form.

Yes. Acesta is the more standard, careful, or slightly formal form. In everyday speech, many speakers would say:

• Ăsta e ultimul mesaj.

That sounds more natural in casual conversation.

Very roughly:

• acesta = more neutral/written/formal
• ăsta = more colloquial/spoken

Both are correct, but they belong to different registers.

Este is the verb to be in the 3rd person singular: is.

So:

• Acesta este ultimul mesaj. = This is the last message.

In spoken Romanian, este is very often shortened to e:

• Acesta e ultimul mesaj.
• Ăsta e ultimul mesaj.

All of these are correct. The full form este sounds a bit more formal or careful.

Because Romanian is expressing the last message, not just a last message.

The adjective ultim means last/final, and here it appears as ultimul, which includes the definite article.

Romanian often attaches the definite article to the end of a word instead of using a separate word like English the.

So:

• ultim mesaj = a last message or just last message in a more indefinite sense
• ultimul mesaj = the last message

This is a very common Romanian pattern.

When an adjective comes before the noun, the definite article is usually attached to the adjective, not the noun:

• ultimul mesaj = the last message
• primul pas = the first step
• noul profesor = the new teacher

If the adjective comes after the noun, Romanian usually marks definiteness on the noun instead:

• mesajul final = the final message

So in your sentence, ultimul mesaj is completely normal: the adjective comes first, so it carries the definite article.

Everything here is singular, and the key noun mesaj is masculine.

Breakdown:

• acesta → masculine singular
• este → 3rd person singular verb
• ultimul → masculine singular definite form
• mesaj → masculine singular noun

Romanian words often have to agree in gender and number, so if the noun changed, some other words would change too.

For example, with a feminine noun:

• Aceasta este ultima carte.
  = This is the last book.

Here acesta becomes aceasta, and ultimul becomes ultima.

Yes, but it means something slightly different in structure.

• Acesta este ultimul mesaj.
  = This is the last message.
• Acest mesaj este ultimul.
  = This message is the last one.

The first sentence uses acesta as a pronoun: this one / this.
The second uses acest mesaj as a full noun phrase: this message.

Both are correct, but they are built differently.

The normal word order is:

• Acesta este ultimul mesaj.

Romanian does allow some flexibility, but not all rearrangements sound equally natural.

For example:

• Acesta este ultimul mesaj. — normal
• Ultimul mesaj este acesta. — possible, but more emphatic, like The last message is this one
• Este acesta ultimul mesaj? — question: Is this the last message?

So yes, word order can change, but it usually changes the emphasis or the sentence type.

A simple learner-friendly pronunciation is:

• acesta ≈ ah-CHES-tah
• este ≈ YES-teh
• ultimul ≈ OOL-tee-mool
• mesaj ≈ meh-SAHZH

A few useful notes:

• ce in acesta sounds like che in chess
• j in mesaj sounds like the s in measure

So the whole sentence sounds roughly like:

• ah-CHES-tah YES-teh OOL-tee-mool meh-SAHZH

Grammatically, acesta is best understood as this one, because it replaces a noun.

But in English, we very often translate it simply as this:

• Acesta este ultimul mesaj.
  = This is the last message.

So:

• grammar explanation: this one
• natural English translation: usually just this

That is very common when comparing Romanian and English.

For a masculine plural noun, the sentence would change like this:

• Aceștia sunt ultimele mesaje.
  = These are the last messages.

You can see several changes:

• acesta → aceștia = these
• este → sunt = are
• ultimul mesaj → ultimele mesaje = the last messages

This shows how Romanian changes words to match number and gender.