A comida é suficiente.

Because a is the feminine singular definite article, meaning the.

In Portuguese, it is very common to use a definite article where English might use no article at all. So a comida can mean:

• the food
• sometimes food in a general/contextual sense, depending on the situation

Here, a comida most naturally means the food.

Since comida is a feminine noun, the article is a, not o.

• a comida = the food
• o alimento = the food / the nourishment

É is from ser, and está is from estar.

In this sentence, é suficiente means is enough / is sufficient as a judgment or statement about the amount. Portuguese normally uses ser here.

• A comida é suficiente. = The food is enough.

Using estar here would sound unusual in most normal contexts. Brazilian Portuguese generally prefers ser suficiente rather than estar suficiente.

A rough way to think about it:

• ser = used for defining, classifying, or stating a quality
• estar = used for states or conditions

Even though enough feels temporary in English, Portuguese still usually says é suficiente.

The accent is important.

• é = is (3rd person singular of ser)
• e = and

So:

• A comida é suficiente. = The food is sufficient.
• A comida e suficiente. = incorrect

The accent shows both the pronunciation and the meaning.

Because suficiente is an adjective that has the same form for masculine and feminine in the singular.

So you get:

• o alimento é suficiente
• a comida é suficiente

Both use suficiente.

Many Portuguese adjectives do change:

• bonito / bonita
• cansado / cansada

But some do not change for gender in the singular:

• suficiente
• interessante
• grande
• feliz

So suficiente works for both masculine and feminine singular nouns.

In the plural, suficiente becomes suficientes.

Examples:

• A comida é suficiente. = The food is enough.
• As comidas são suficientes. = The foods / meals are sufficient.
• Os recursos são suficientes. = The resources are sufficient.

So the adjective does not change for gender, but it does change for number:

• singular: suficiente
• plural: suficientes

Yes, but it means something slightly different in structure.

• A comida é suficiente. = The food is enough.
• comida suficiente = enough food / sufficient food

So:

• Há comida suficiente. = There is enough food.
• A comida é suficiente. = The food is enough.

In other words:

• é suficiente = adjective after the verb, describing the subject
• comida suficiente = adjective directly modifying the noun

Both are correct, but they are built differently.

Usually, no—not in normal everyday Portuguese.

Comida é suficiente sounds incomplete or unnatural in most contexts. Portuguese generally prefers the article here:

• A comida é suficiente.

Without the article, it might only sound acceptable in very special styles, like headlines, slogans, or very abstract statements. For ordinary speech, use a comida.

This is one of the places where Portuguese uses articles more often than English.

It can mean both, depending on context.

Comida often means:

• food in general
• a meal
• cooked food
• what there is to eat

So A comida é suficiente could mean:

• The food is enough
• The meal is enough

The exact meaning depends on the situation.

For example:

• At dinner, it may mean the meal is enough.
• In a broader discussion, it may mean the food supply is enough.

A helpful approximate pronunciation is:

ah koh-MEE-dah eh soo-fee-SYEN-chee

A few notes:

• A sounds like ah
• comida = koh-MEE-dah
• é = eh
• suficiente in Brazil is roughly soo-fee-SYEN-chee

The final te in many Brazilian accents sounds like chee.

A more natural connected pronunciation may sound something like:

a comida é suficiente
→ ah koh-MEE-da eh soo-fee-SYEN-chee

Yes, it is grammatical and natural.

It sounds like a clear, neutral statement meaning that the food amount is enough.

Depending on context, native speakers might also say things like:

• Tem comida suficiente. = There’s enough food.
• A comida basta. = The food is enough.
• Já é o suficiente. = It’s already enough.

But A comida é suficiente is perfectly correct and natural.