Questions & Answers about 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.
Because the subject is singular: o karaokê.
So:
- O karaokê tem uma cabine.
- Os karaokês têm cabines.
The circumflex in têm helps show the plural form.