First time, the = unuafoje; unuan fojon; en launua fojo.
Inter la deka kaj dek-unua matene, mi renkontis mian amikon = Between 10 and 11 o'clock in the morning I met my friend.
De, as:--La unua vorto de la linio = The first word of the line.
En la unua tempo = At the outset (first time), at first.
En la unua ĉe tia longa By the first for such a veturo.
Tio venis de (or, el) lia unua eraro = That came from his first error.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "unua" in a variety of sentences. We hope that you will now be able to make sentences using this word.