Fazer o check-in vs. dar entrada
While both fazer o check-in and dar entrada refer to the process of arriving and registering, their usage depends heavily on the specific location and context. fazer o check-in is a loanword from English used predominantly in travel, while dar entrada is the traditional Portuguese phrase used for formal registration in various establishments.
Fazer o check-in
A1This phrase is a direct adoption of the English term. It is the exclusive term used for air travel (airports) and is extremely common in modern hotel contexts. It implies the specific administrative task of confirming your presence to get a boarding pass or a room key.
Nós precisamos fazer o check-in duas horas antes do voo partir.
(We need to check in two hours before the flight departs.)
Você pode fazer o check-in pelo aplicativo para economizar tempo.
(You can check in via the app to save time.)
Só podemos fazer o check-in no hotel depois das 14 horas.
(We can only check in at the hotel after 2 PM.)
Dar entrada
B1Literally meaning to give entry, this is the formal Portuguese way to describe registering your arrival. It is commonly used for hotels, inns, and guesthouses. Unlike its counterpart, it is also the standard phrase for being admitted to a hospital or clinic, but it is almost never used for flights.
O turista foi à receção para dar entrada no hotel.
(The tourist went to the reception to check in at the hotel.)
Para dar entrada, é necessário apresentar um documento de identificação.
(To register (check in), it is necessary to present an identification document.)
O paciente acabou de dar entrada na emergência.
(The patient just checked into the emergency room.)
Summary
In short, use fazer o check-in for all airport situations and casual hotel interactions. Use dar entrada when speaking more formally about accommodation or when referring to hospital admissions. You cannot use dar entrada for a flight.