Fa plus a length of time means ago and points at a finished moment: fa uns anys. Des de fa plus the same phrase means for that long and describes something still going on. Des de plus a date means since.
Examples
- Fa uns anys vivia a València.
- A few years ago I was living in Valencia.
- Visc aquí des de fa tres anys.
- I have been living here for three years.
- De petit anava a la platja cada estiu.
- As a child I went to the beach every summer.
The mistake to avoid
Fa tres anys is ago; des de fa tres anys is still true today.
Where this fits in
El passat i l'últim cap de setmana, Catalan A2: Talk about the past: yesterday, last weekend, and travel memories.