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"On time" is a phrase which is often translated as "a tiempo", and "punctual" is an adjective which is often translated as "puntual". Learn more about the difference between "on time" and "punctual" below.
on time(
an
taym
)A phrase is a group of words commonly used together (e.g., once upon a time).
1. (punctual)
a. a tiempo
The delivery guy didn't deliver on time, so the pizza came out of his pay.El repartidor no llegó a tiempo, así que le sacaron la pizza de su salario.
They said the plane would arrive on time, but I have my doubts.Dijeron que el avión llegaría a tiempo, pero tengo mis dudas.