O karaokê tem uma cabine.

Portuguese uses definite articles more often than English. So o karaokê is natural when you mean the karaoke place or the karaoke venue.

In English, you might often just say Karaoke has a booth in some contexts, but in Portuguese, using o is very common when talking about a specific thing already known in the conversation.

Yes. In this sentence, karaokê is treated as a masculine noun, so it takes o.

That does not necessarily mean there is a deep logical reason for the gender; many borrowed words simply get assigned a grammatical gender in Portuguese. Here, the standard and natural form is o karaokê.

Because the subject is singular: o karaokê.

• tem = has for ele/ela/você or any singular noun
• têm = have for eles/elas/vocês or any plural noun

So:

• O karaokê tem uma cabine.
• Os karaokês têm cabines.

The circumflex in têm helps show the plural form.

Tem is the present tense of the verb ter, which usually means to have.

Here it means has:

• O karaokê tem uma cabine. = The karaoke place has a booth/private room.

In Brazilian Portuguese, tem is also very commonly used in everyday speech with the meaning there is/there are, but in this sentence the structure is straightforwardly subject + has + object.

Because cabine is a feminine noun in Portuguese.

So:

• uma cabine
• a cabine

This is a good reminder that noun gender in Portuguese does not always match the final letter. Even though cabine ends in -e, it is feminine.

Not always. Cabine often means booth, stall, cubicle, or private room/compartment, depending on context.

In a karaoke context, cabine often suggests a private singing booth or room, not a wooden cabin in the English sense.

So it is better to think of cabine here as something like:

• booth
• private room
• karaoke room

Yes. It follows a very standard Portuguese pattern:

subject + verb + object

• O karaokê = subject
• tem = verb
• uma cabine = object

So for an English speaker, the basic structure feels familiar:

• The karaoke place has a booth.

In Brazilian Portuguese, karaokê is pronounced with the stress on the last syllable: ka-ra-o-KÊ.

A helpful approximation is:

• kah-rah-oh-KEH

The accent mark ê shows that the final syllable is stressed and that the vowel is a closed e sound.

The circumflex in ê tells you about both stress and vowel quality.

In karaokê:

• the stress falls on the last syllable
• the final vowel is a closed e sound

So the accent helps show the standard pronunciation: karaokê.

Yes. That is also correct, but it is a different structure.

• O karaokê tem uma cabine. = The karaoke place has a booth.
• Há uma cabine no karaokê. = There is a booth in the karaoke place.

Both are grammatical. The first presents the karaoke place as the possessor. The second presents the booth as something that exists there.

In everyday Brazilian Portuguese, tem is often preferred in speech even for existential meanings, so you may also hear:

• Tem uma cabine no karaokê.

Because uma cabine is the direct object of tem.

The verb ter normally takes a direct object with no preposition:

• Ela tem um carro.
• O hotel tem piscina.
• O karaokê tem uma cabine.

So nothing needs to be inserted between tem and uma cabine.

In theory, karaokê can refer to karaoke as an activity or entertainment format, but in this sentence the use of tem uma cabine strongly suggests a place, establishment, or venue.

An activity does not usually have a booth, but a karaoke bar or karaoke venue does. So the context pushes the meaning toward the karaoke place.

You would change the article, the noun, the verb, and probably the object too:

• Os karaokês têm cabines.

Changes:

• o → os
• karaokê → karaokês
• tem → têm
• uma cabine → cabines or umas cabines

A more natural plural sentence is usually:

• Os karaokês têm cabines. = Karaoke places have booths/private rooms.