For last, passat follows the noun and agrees with it: dissabte passat, la setmana passada. For ago, fa comes before the amount of time: fa dos dies. These markers open or close the sentence rather than sitting inside the verb.
Examples
- El cap de setmana passat vaig anar a la platja.
- Last weekend I went to the beach.
- Vaig conèixer la Marta fa dos anys.
- I met Marta two years ago.
- L'altre dia vam quedar per sopar.
- The other day we met up for dinner.
The mistake to avoid
Fa comes before the time: fa dos dies, not "dos dies fa".
Where this fits in
El passat i l'últim cap de setmana, Catalan A2: Talk about the past: yesterday, last weekend, and travel memories.