A base é forte.

Because base is a feminine noun in Portuguese, so it takes the feminine singular article a.

• a base = the base
• uma base = a base

This is something you usually have to learn with the noun itself, because grammatical gender in Portuguese does not always match the noun’s ending.

In Portuguese, noun gender is not determined only by the final letter. While many feminine nouns end in -a and many masculine nouns end in -o, there are lots of exceptions.

So with base, you simply learn it as:

• a base (feminine)

This is very common in Portuguese. A noun ending in -e can be masculine or feminine.

É is the present tense of ser, and está is the present tense of estar.

In A base é forte, Portuguese uses ser because the sentence describes a characteristic or defining quality of the subject.

• ser = to be, for identity, definition, more essential traits
• estar = to be, for states, conditions, locations

So:

• A base é forte = the base is strong / the base is solid

If you said A base está forte, it would sound more like a temporary condition or a current state, which is less natural in many contexts.

The accent mark shows that é is pronounced as a stressed vowel and also distinguishes it from e.

• é = is
• e = and

So this accent is important both for pronunciation and for meaning.

Because forte is one of many Portuguese adjectives that have the same form for masculine and feminine singular.

Compare:

• o homem forte
• a base forte

The adjective only changes in the plural:

• o homem forte
• a base forte
• os homens fortes
• as bases fortes

So forte works for both masculine and feminine in the singular.

A simple pronunciation guide is:

• a = ah
• base ≈ BAH-zee or BAH-see depending on accent
• é = like eh
• forte ≈ FOR-chee or FOR-tee depending on region

A broad Brazilian-style approximation: ah BAH-see eh FOR-chee

A few helpful notes:

• base is stressed on the first syllable: BA-se
• forte is stressed on the first syllable: FOR-te
• In many Brazilian accents, the final -e sounds like ee
• In many accents, t before that final e can sound like ch, so forte may sound like FOR-chee

Usually, A base é forte sounds more natural as a complete normal sentence.

Leaving out the article can sound:

• more like a headline
• more abstract or generic
• less natural in everyday speech, depending on context

So for most learners, the safest choice is:

• A base é forte

The normal order is:

article + noun + verb + adjective

So:

• A base = subject
• é = verb
• forte = adjective

This is the most neutral and standard order in Portuguese: A base é forte.

You might sometimes see a different order for emphasis, but this version is the ordinary one.

The plural is:

As bases são fortes.

Here is what changes:

• a → as
• base → bases
• é → são
• forte → fortes

So singular and plural are:

• A base é forte.
• As bases são fortes.

No. Forte can describe several kinds of strength, depending on context.

It can mean:

• physically strong
• solid or sturdy
• intense
• powerful
• strong in a figurative sense

So in A base é forte, forte could mean something like:

• structurally strong
• solid
• reliable
• robust

The exact nuance depends on the context.

It is neutral. It works in both formal and informal Portuguese.

• In conversation, it sounds completely natural.
• In writing, it is also fine.
• There is nothing especially slangy or especially formal about it.

So it is a very standard Portuguese sentence structure.