O carvão e o acendedor estão aqui.

Because both nouns are masculine singular, so they take the masculine singular definite article o.

• o carvão = the charcoal
• o acendedor = the lighter / fire starter / igniter

Portuguese also uses definite articles more often than English does, so keeping them here sounds natural.

Because the subject is plural: o carvão e o acendedor.

When two singular nouns are joined by e meaning and, they form a plural subject, so the verb must also be plural:

• está = is
• estão = are

So:

• O carvão está aqui = The charcoal is here
• O carvão e o acendedor estão aqui = The charcoal and the lighter are here

Portuguese normally uses estar for location.

So if you want to say that something is physically somewhere, you usually use estar:

• O carvão está aqui
• Eles estão em casa

Ser is used for things like identity, description, profession, origin, and time, but not for ordinary location.

Acendedor is something used to light a fire or flame. Depending on the situation, it could mean:

• a lighter
• a fire starter
• an igniter

In everyday Brazilian Portuguese, isqueiro is often the more common word for a small pocket lighter. Acendedor is broader and can sound a bit more general or functional.

Yes. Carvão is singular here, and that is completely normal.

Like English charcoal, it can refer to the material in a general or collective way. Portuguese still treats it as a singular noun in sentences like this:

• O carvão está molhado
• O carvão acabou

If you were talking about separate pieces or types, then a plural form could appear in a different context, but the singular is the normal form here.

A rough English-style guide is kar-VAW̃, with the stress on the last syllable.

Important points:

• car sounds roughly like kar
• vão has the very common Portuguese nasal ending -ão
• the last syllable is stressed: car-VÃO

That final sound does not exist exactly in English, so the closest approach is to nasalize the vowel and avoid making it sound like a full English own.

That mark is a tilde: ã.

It shows that the vowel is nasal. So carvão is not pronounced with a plain a sound. Instead, the air goes through both the mouth and the nose.

This nasal quality is one of the most important pronunciation features in Portuguese, especially in endings like -ão.

In Brazilian Portuguese, the conjunction e meaning and is usually pronounced like ee in see.

So o carvão e o acendedor often sounds roughly like:

o carvão i o acendedor

That is normal connected speech.

You can in very special contexts, such as notes, labels, inventory lists, or very telegraphic speech. But in normal everyday Portuguese, it sounds more natural to keep the articles:

O carvão e o acendedor estão aqui.

Portuguese generally uses articles more often than English, so learners should not drop them too quickly.

Both can mean here, but aqui is the most neutral and safest choice for learners.

• aqui = standard, very common
• cá = also common in some expressions, but can feel more informal or stylistic depending on context

For a sentence like this, aqui is the most straightforward option.

Yes, that alternative is possible.

• O carvão e o acendedor estão aqui = neutral, standard order
• Estão aqui o carvão e o acendedor = possible, often with more focus on the location or as a way of presenting what is here

For learners, the original order is the best default.

In this sentence, the article tells you: both use o, which is masculine singular.

So even if you do not already know the noun gender, the sentence shows it:

• o carvão
• o acendedor

As you learn Portuguese, always pay attention to nouns together with their articles, because that is one of the easiest ways to remember gender correctly.