A comida está ruim.

Comida is a feminine singular noun, so the definite article that matches it is a.

In this sentence, a comida usually means the food in a specific situation: the food here, the food we are eating, the dish that was served, and so on.

If you remove the article and say just comida, it sounds less natural in a normal full sentence like this. Portuguese uses articles more often than English does.

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

Here, está is used because the sentence describes the food’s current condition or how it seems right now. The idea is that, at this moment, the food is bad.

Compare:

• A comida está ruim. = The food is bad right now / tastes bad / has turned out badly.
• A comida é ruim. = The food is bad in general / the food is low-quality by nature.

In everyday situations, when reacting to a meal in front of you, está ruim is usually the more natural choice.

The accent mark in está shows the stressed syllable and is part of the correct spelling.

It also helps distinguish it from esta, which means this for a feminine noun.

So:

• está = is
• esta = this

That accent is important both for pronunciation and meaning.

Because ruim is functioning as an adjective after the verb estar.

The structure is:

• A comida = subject
• está = verb
• ruim = adjective describing the subject

So this is like:

• A comida está boa.
• O café está frio.
• A sopa está salgada.

This is not the same as putting an adjective directly next to the noun, as in comida ruim, which means bad food as a noun phrase.

It does not change for gender in the singular:

• o livro ruim
• a comida ruim

But it does change in the plural:

• os livros ruins
• as comidas ruins

So in your sentence, ruim stays the same because comida is singular.

In Brazil, ruim is commonly pronounced as two syllables, roughly ru-im.

A simple learner-friendly approximation is:

• roo-EEN with a nasal ending

The exact sound varies by region, but the important thing is that it is usually not pronounced like a single English-style syllable. Also, the final sound is nasalized.

Grammatically, má is the feminine form of mau, and it can mean bad. But for food, ruim is much more common and natural in Brazilian Portuguese.

So:

• A comida está ruim. = very natural
• A comida está má. = grammatical, but less idiomatic in everyday Brazilian speech

For describing food quality, taste, or condition, learners should usually prefer ruim.

Yes. In spoken Brazilian Portuguese, tá is extremely common as a short form of está.

So you will often hear:

• A comida tá ruim.

This is natural and very common in conversation. In more formal writing, está is preferred.

Yes. In real conversation, A comida está ruim can cover several related ideas, depending on context:

• it tastes bad
• it is not good
• it turned out badly
• it has gone bad
• it is of poor quality right now

If you need to be more specific, Portuguese can say that too:

• A comida está com gosto ruim. = The food tastes bad.
• A comida estragou. = The food went bad / spoiled.
• A comida não está boa. = The food isn’t good.

But the original sentence is broad and very natural.

In Brazilian Portuguese, you can often make a yes/no question just by using question intonation:

• A comida está ruim?

The word order usually stays the same. In writing, you just add the question mark. In speech, your voice rises at the end.

A very common informal version is:

• A comida tá ruim.

That is probably what you would hear most often in casual Brazilian speech. The meaning is the same; the only change is está → tá.