The Portuguese word for garage is
garagem

Gender

The gender of garagem is feminine. E.g. a garagem.

The plural of garagem is garagens.

garagem
1. n-f. garage (place to store a car)
2. n-f. garage (place where cars are repaired)

mecânica
1. adj. feminine singular of mecânico

oficina
1. n-f. workshop
A pintura é atribuída à oficina de Rubens. - The painting is attributed to the workshop of Rubens.
O escultor trabalhava sempre até tarde na sua oficina. - The sculptor always worked late in his workshop.
2. n-f. automobile garage (a place where cars are serviced and repaired)
Hoje eu levei o meu carro à oficina. - I took my car into the garage today.