Poeta notus in urbe habitat.

Because poeta is a first-declension masculine noun. Many first-declension nouns are feminine, but some nouns referring to male professions or roles are masculine, and poeta is one of them.

This word comes from Greek, and Latin kept its first-declension shape. So even though -a often suggests a feminine noun, you cannot rely on the ending alone. You have to learn the noun’s gender as well.

That is why the adjective is notus, not nota.

Because adjectives in Latin must agree with the noun they describe in gender, number, and case.

Here, poeta is:

• masculine
• singular
• nominative

So the adjective must match it:

• notus = masculine singular nominative

If the noun were feminine, you would expect nota instead.

Latin word order is much more flexible than English word order. An adjective can come before or after its noun.

So poeta notus means the famous poet or the well-known poet, even though the adjective comes after the noun.

This noun + adjective order is very common in Latin. It does not sound strange in Latin the way it would in English.

Poeta is nominative singular, which is the case usually used for the subject of the sentence.

We know it is the subject because:

• habitat means he/she lives or lives
• the person doing the action of living is poeta

So poeta is the subject: the poet.

Urbe is ablative singular of urbs, urbis meaning city.

It is ablative because it follows in in the sense of location:

• in urbe = in the city

With places where someone or something is located, in normally takes the ablative.

Because Latin distinguishes between:

• location: being in a place
• motion toward a place

So:

• in urbe = in the city / located there
• in urbem = into the city / moving into it

Since habitat describes where the poet lives, not movement into the city, Latin uses in + ablative: in urbe.

Habitat is the verb. It is:

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

So it means he lives, she lives, or more literally lives.

Because the subject is poeta, we understand it as the poet lives.

Latin does not have articles like English the and a/an.

So poeta can mean:

• a poet
• the poet

And in urbe can mean:

• in a city
• in the city

Usually the context tells you which English article is best.

Yes. Latin word order is flexible because the endings show the grammatical relationships.

For example, these could all express roughly the same basic idea:

• Poeta notus in urbe habitat.
• In urbe poeta notus habitat.
• Habitat in urbe poeta notus.

However, changing the order can change the emphasis or style. The given sentence is a straightforward, natural way to say it.

It can mean either, depending on context.

Notus literally means known, but in many sentences it is best translated as well-known or famous.

So poeta notus could be understood as:

• a known poet
• a well-known poet
• a famous poet

The exact English wording depends on the context and on the translation you were shown.