Today, we’re going to examine how to use “ao” as a preposition. Here, it is used as “upon” or “when.”

Ao descobrir o rato no quarto, ela deu um grito. When she discovered the mouse in her room, she screamed.

Ao encontrar o garoto perdido, ficamos aliviados. Upon finding the lost boy, we felt relieved.

Fiquei feliz ao embarcar no avião. I felt happy when I got on the plane.

Expressions with ao

ao vivo = live

ao dente = al dente

ao fim de tudo = at the end

ao fim e ao cabo = in the end/in conclusion

Can you think of any other expressions using ao?