O caule está verde e forte.

O is the definite article, meaning the. Portuguese uses definite articles more often than English does, so o caule is the normal way to say the stem.

• o = the for a masculine singular noun
• caule = stem / stalk

So o caule is the natural full subject of the sentence.

Yes, caule is masculine, which is why the sentence uses o.

In Portuguese, noun gender is grammatical, so you usually have to learn it together with the noun:

• o caule
• not a caule

The ending -e does not automatically tell you the gender. Many nouns ending in -e can be either masculine or feminine, so the article is often your best clue.

Portuguese has two common verbs for to be: ser and estar.

Here, está is used because verde and forte are being presented as the stem’s current condition or state.

• estar often describes a condition, appearance, or state
• ser often describes identity, essence, or a more permanent characteristic

So O caule está verde e forte sounds like the stem is currently healthy-looking or in a good growing state.

If you said O caule é verde, that could sound more like green is its defining color in a general sense.

Está is the third-person singular form of estar in the present tense.

That form is used with subjects like:

• ele = he / it
• ela = she / it
• você = you
• o caule = the stem

So:

• o caule está
• ele está

The accent in está is important in spelling.

Because they are predicate adjectives describing the subject after the linking verb estar.

The structure is:

• subject + estar + adjective(s)

So:

• O caule = subject
• está = is
• verde e forte = green and strong

This works very much like English The stem is green and strong.

Yes. In Portuguese, adjectives normally agree with the noun in gender and number.

Here, caule is:

• masculine
• singular

So the adjectives are in singular form too:

• verde
• forte

These two adjectives happen to have the same form for masculine singular and feminine singular:

• o caule verde
• a folha verde
• o caule forte
• a raiz forte

But in the plural they change:

• verdes
• fortes

Because not all Portuguese adjectives have separate masculine and feminine endings.

Some adjectives change:

• bonito / bonita
• verde does not work like that
• forte does not work like that

So the singular forms are:

• masculine singular: verde, forte
• feminine singular: verde, forte

Only the plural changes:

• verdes
• fortes

Here forte means strong.

For a plant stem, it suggests something like:

• sturdy
• healthy
• robust
• not weak or damaged

So in this sentence, forte is describing the stem as physically strong or healthy.

A simple approximate pronunciation is:

OH KAH-oo-lee es-TAH VEHR-jee ee FOR-chee

A few helpful notes for Brazilian Portuguese:

• caule sounds roughly like KAH-oo-lee
• está has stress on the last syllable: es-TAH
• verde often sounds like VEHR-jee in many Brazilian accents
• forte often sounds like FOR-chee in many Brazilian accents
• e meaning and is usually pronounced like ee

Pronunciation varies by region, but this is a useful Brazilian starting point.

Usually no, not in a normal complete sentence.

Portuguese generally wants an article here, so O caule está verde e forte sounds natural and complete.

Dropping the article might sound unnatural or like a dictionary label, note, headline, or very special context rather than standard everyday speech.

Yes. That is grammatically correct.

When you connect two adjectives with e (and), changing the order is usually possible:

• verde e forte
• forte e verde

The original order may feel a little more natural if you first describe appearance (verde) and then condition (forte), but both are fine.