Expresia aceasta are alt sens în acest mesaj.

Both are correct.

• expresia aceasta = the noun comes first, then the demonstrative
• această expresie = the demonstrative comes first

In Romanian, both patterns are common. The version with the demonstrative after the noun often sounds very natural in everyday speech. The version with the demonstrative before the noun can sound a bit more neutral or slightly more formal/written.

Also note the form changes:

• before the noun: această
• after the noun: aceasta

So:

• această expresie
• expresia aceasta

Because expresia means the expression.

The base noun is expresie = expression. Romanian usually puts the definite article at the end of the noun, not as a separate word like English the.

So:

• expresie = expression
• expresia = the expression

That is why you get expresia aceasta rather than expresie aceasta.

Are is the 3rd person singular of a avea = to have.

So are means has.

Romanian commonly says that a word or expression has a meaning:

• are sens
• are alt sens

Using este would not fit this structure. Romanian does not normally say the expression is another meaning for this idea. If you wanted a different structure, you could say something like înseamnă altceva = means something else.

Actually, both are correct.

• acest mesaj = this message
• mesajul acesta = this message

The difference is mainly in structure:

• if the demonstrative comes before the noun, the noun usually does not take the definite ending: acest mesaj
• if the demonstrative comes after the noun, the noun usually does take the definite ending: mesajul acesta

So these are both fine:

• în acest mesaj
• în mesajul acesta

But mesajul acest is not correct.

Because mesaj is a masculine singular noun, and Romanian demonstratives have to agree with the noun.

So:

• masculine singular: acest mesaj
• feminine singular: această expresie

That same agreement rule also explains other words in the sentence.

Because sens is masculine singular.

The adjective alt has to agree with the noun:

• masculine singular: alt sens
• feminine singular: altă idee
• masculine plural: alți oameni
• feminine plural: alte expresii

So alt sens is correct because sens is masculine.

Both are possible:

• are alt sens
• are un alt sens

The version without un is a bit more compact and direct. Romanian often allows this, especially with a avea.

Also, alt already signals the idea of another/different, so the sentence is still perfectly clear without un.

What you cannot say here is altul sens. Altul is used on its own, not directly before a noun.

For example:

• Are alt sens. = correct
• Are un alt sens. = correct
• Are altul sens. = not correct

Here, sens means meaning.

In Romanian, sens can mean:

• sense
• meaning
• direction in some contexts

With language, words, or expressions, it often means meaning, sense, or nuance.

A related word is înțeles, which can also mean meaning or understanding, but sens is very natural in this sentence.

Yes, absolutely.

Romanian speakers naturally use both patterns:

• noun + demonstrative after it: expresia aceasta
• demonstrative + noun: acest mesaj

Mixing them in one sentence is not wrong at all.

If you want, you could also make the whole sentence parallel in either direction:

• Această expresie are alt sens în acest mesaj.
• Expresia aceasta are alt sens în mesajul acesta.

All of these are correct.

Yes. Romanian word order is fairly flexible.

For example, you could also say:

• În acest mesaj, expresia aceasta are alt sens.

That version emphasizes the context in this message a bit more. The original sentence sounds neutral and natural.

Very roughly:

eks-pre-SI-a a-CEAS-ta A-re alt sens în a-CEST me-SAJ

A few helpful notes:

• expresia has stress on SI
• aceasta has stress on CEAS
• mesaj has stress on the last syllable: SAJ
• j in mesaj sounds like the s in measure
• ce in acest and aceasta sounds like che in check

The vowel in în does not match a common English vowel exactly, so it may take some listening practice.