Am trimis un mesaj vocal.

Yes. In this sentence, am is the 1st person singular present form of the auxiliary verb a avea (to have), and it is used to build the perfectul compus, a very common Romanian past tense.

So:

• am trimis = I sent / I have sent

This is similar to English have sent, but in Romanian it is also very commonly used where English would simply use sent.

Trimis is the past participle of a trimite (to send).

So the structure is:

• am = auxiliary
• trimis = past participle

Together:

• am trimis = I sent / I have sent

This pattern is extremely common in Romanian:

• am văzut = I saw / I have seen
• am făcut = I did / I have done
• am spus = I said / I have said

Romanian often drops the subject pronoun when it is clear from the verb.

Here, am already tells you the subject is I, so eu is not necessary.

• Am trimis un mesaj vocal. = normal, natural
• Eu am trimis un mesaj vocal. = I sent a voice message

Adding eu usually gives extra emphasis, contrast, or clarity.

Un is the indefinite article meaning a or an.

• un mesaj = a message

Because mesaj is a masculine singular noun, the correct article is un.

Compare:

• un băiat = a boy
• un mesaj = a message
• o fată = a girl

In Romanian, adjectives often come after the noun.

So:

• mesaj vocal = voice message / literally message vocal

This is a very common Romanian word order:

• carte interesantă = interesting book
• om bun = good person
• mesaj vocal = voice message

English often puts adjectives before the noun, but Romanian often puts them after.

Vocal is an adjective describing mesaj.

Because mesaj is masculine singular, the adjective also appears in its masculine singular form:

• un mesaj vocal

If the noun changed, the adjective might change too:

• un mesaj vocal = a voice message
• două mesaje vocale = two voice messages

So Romanian adjectives agree with the noun in gender and number.

Yes, mesaj vocal is a normal and natural way to say voice message.

Depending on context, Romanians may also say things like:

• mesaj audio
• mesaj înregistrat in some situations

But mesaj vocal is a very standard everyday expression, especially for messaging apps.

Yes. Romanian perfectul compus often covers both meanings.

So:

• Am trimis un mesaj vocal.

can mean:

• I sent a voice message.
• I have sent a voice message.

Which translation sounds better depends on the context in English. Romanian does not always make the same distinction English does between simple past and present perfect.

A rough English-friendly guide is:

• am tree-MEES oon मे-SAZH vo-KAL

A few notes:

• tr in trimis is pronounced clearly, not softened
• i in trimis is a normal Romanian ee sound
• j in mesaj sounds like the s in measure
• c in vocal is a hard k sound

A more careful approximation:

• Ahm tree-MEES oon meh-SAHZH voh-KAHL

Because in this tense, the person is shown mainly by the auxiliary, not by changing the participle.

Compare:

• am trimis = I sent
• ai trimis = you sent
• a trimis = he/she sent
• am trimis = we sent
• ați trimis = you all sent
• au trimis = they sent

Notice that trimis stays the same, while the auxiliary changes.

Yes, but the basic order here is the most neutral:

• Am trimis un mesaj vocal.

Romanian allows some flexibility for emphasis:

• Un mesaj vocal am trimis. = It was a voice message that I sent.
• Am trimis vocal un mesaj. = unnatural in this meaning

So while Romanian is somewhat flexible, not every rearrangement sounds natural. The original sentence is the standard choice.

The dictionary form is a trimite, meaning to send.

Important forms:

• a trimite = to send
• trimit = I send
• am trimis = I sent / I have sent

Learners should notice that the participle trimis does not look exactly like the infinitive trimite, so it is worth memorizing.

It would be:

• Am trimis un mesaj vocal.

Interestingly, this is identical in writing to I sent a voice message.

Romanian distinguishes the two through context, or by adding the pronoun if needed:

• Eu am trimis un mesaj vocal. = I sent a voice message.
• Noi am trimis un mesaj vocal. = We sent a voice message.

So sometimes Romanian relies on context more than English does.