Saque vs. serviço
In the context of sports like tennis, volleyball, and table tennis, the terminology for the starting shot varies significantly between Portuguese varieties. While saque is the standard term used in Brazil, serviço is the preferred word in Portugal.
Saque
B1This is the exclusive term in Brazilian Portuguese for serving a ball to start a point in sports. It is derived from the verb sacar (to serve/to pull out). In Portugal, this word is widely understood but serviço is preferred for the action.
O saque dele atingiu uma velocidade impressionante.
(His serve reached an impressive speed.)
Ela errou o saque e a bola ficou na rede.
(She missed the serve and the ball stayed in the net.)
No vôlei, o saque jornada nas estrelas é raro hoje em dia.
(In volleyball, the skyball serve is rare nowadays.)
Quem vai fazer o saque no próximo set?
(Who is going to do the serve in the next set?)
Ele ganhou o ponto direto no saque.
(He won the point directly on the serve.)
Serviço
A2In European Portuguese (Portugal), this is the standard sports term for the serve. It is derived from the verb servir. While serviço exists in Brazil, it is almost exclusively used there to mean a job, military duty, or customer service, rather than a sports move.
O tenista espanhol perdeu o seu jogo de serviço.
(The Spanish tennis player lost his service game.)
Foi um serviço muito potente.
(It was a very powerful serve.)
Agora é o teu serviço, por favor vai para a linha de fundo.
(Now it is your service, please go to the baseline.)
A equipa portuguesa melhorou muito o seu serviço.
(The Portuguese team improved their service a lot.)
Falhou o primeiro serviço, mas acertou o segundo.
(He missed the first serve, but got the second one right.)
Summary
The choice depends entirely on geography. Use saque when discussing sports in Brazil and serviço when in Portugal. Using serviço to mean a sports serve in Brazil may cause confusion, as locals usually interpret that word as work or job context.