先前 (xiān qián): previously

Previously he didn't like sports; ever since he joined the company basketball team, he now plays basketball twice a week.

This restaurant used to be deserted, but after changing chefs, it's now full of guests every night.

I previously thought learning Chinese was very difficult, but after sticking with it for half a year, I found it wasn't actually that scary.

He previously worked at a small company; after gaining experience, he switched jobs last year to a well-known enterprise.