Poeta vitam aeternam laudat.

Because poeta is in the nominative singular, the case normally used for the subject of a sentence.

In this sentence:

• poeta = nominative singular
• vitam aeternam = accusative singular

So poeta is the one doing the action, and vitam aeternam is receiving the action.

This is a very common beginner question. Poeta belongs to the first declension, which often has nouns ending in -a, but some first-declension nouns are masculine, especially words for professions or roles originally borrowed from Greek.

So:

• poeta = poet
• gender: masculine
• declension: first declension

Its ending looks like many feminine nouns, but its grammatical gender is masculine.

Because vitam is the accusative singular form of vita.

Latin changes noun endings to show their role in the sentence. Here, life is the direct object of laudat, so it must be in the accusative:

• nominative: vita
• accusative: vitam

English usually shows this role by word order, but Latin often shows it by endings.

Because the adjective must agree with the noun it describes.

Here, aeternam describes vitam, so it matches it in:

• gender: feminine
• number: singular
• case: accusative

So:

• vitam = feminine singular accusative
• aeternam = feminine singular accusative

This is called adjective agreement.

No. Latin word order is more flexible than English word order.

You could also see:

• Poeta aeternam vitam laudat.

That would mean the same basic thing. Latin uses endings more than position to show grammar.

That said, noun + adjective is a very normal and common order, so vitam aeternam looks perfectly natural.

Laudat is the verb, and it tells you several things at once.

It is:

• present tense
• active voice
• indicative mood
• third person singular

So it means he/she/it praises or is praising, depending on context.

Since the subject is poeta, the meaning is the poet praises.

Classical Latin has no articles like English the or a/an.

So poeta can mean:

• a poet
• the poet

and vitam aeternam can mean:

• eternal life
• the eternal life

Context usually makes it clear which is best in translation.

Yes. That is still grammatical Latin.

Because the endings already show the roles:

• poeta is still the subject
• vitam aeternam is still the object

Changing the order may change emphasis, but not the core meaning.

For example:

• Poeta vitam aeternam laudat = neutral order
• Vitam aeternam poeta laudat = stronger focus on eternal life
• Laudat poeta vitam aeternam = stronger focus on the action praises

Because of agreement.

Both words are:

• feminine
• singular
• accusative

That strongly signals that aeternam modifies vitam. In other words, they form the phrase eternal life.

Latin often lets you identify connected words by matching endings, even when they are not right next to each other.

A learner often wants to know what forms to look up in a dictionary. They are:

• poeta, poetae = poet
• vita, vitae = life
• aeternus, aeterna, aeternum = eternal
• laudo, laudare, laudavi, laudatus = praise

The sentence uses these forms:

• poeta from poeta
• vitam from vita
• aeternam from aeterna / aeternus
• laudat from laudo

A simple classroom-style pronunciation would be something like:

POE-ta WEE-tam eye-ter-nam LOW-dat

A more Classical-style approximation:

• poeta = po-AY-ta
• vitam = WEE-tam
• aeternam = eye-TER-nam
• laudat = LOW-dat

A few helpful points:

• Latin v is often pronounced like English w in restored Classical pronunciation.
• ae is usually like eye.
• Stress generally falls on the second-to-last syllable if it is heavy; otherwise on the third-to-last. So:
  • po-É-ta
  • ví-tam
  • ae-tér-nam
  • láu-dat

Not as written.

The endings show that:

• poeta is nominative = subject
• vitam aeternam is accusative = direct object

So the poet is the one doing the praising.

If you wanted eternal life to be the subject, you would need:

• Vita aeterna poetam laudat.

There:

• vita aeterna is nominative
• poetam is accusative

That is one of the biggest differences between Latin and English: endings matter more than word order.