How do you say I used to live in Australia in french?

Answer 1

"J'habitais en Australie." It sounds a little bit bare to say it that way -- you would probably add something like "pendant quelques années" (=for a few years) or "quand j'étais enfant" (=when I was a child). Regardless, it would get your message across. :-)

Answer 2

"Je l'aimais avant." (I liked it before)

"J'aimais..." (I liked/used to like...)