There are several verbs that you will use often to talk about what something was like (giving a description).
Être is a verb commonly used for the imperfect tense, for example:
- j'étais - I was → j'étais fatigué - I was tired
- nous étions heureux - we were happy
C'était (meaning it was) + an adjective can be used to give your opinion on something:
- c'était fantastique ! - it was great!
- c'était difficile - it was difficult
Note that c'est is a useful set phrase in the present tense meaning 'it is'. Here it is used in its past form - c'était. C'/Ce are treated like il/elle/on when adding endings.
You'll often need to use avoir too:
- j'avais - I used to have/I had → j'avais mal à la gorge - I had a sore throat
- il y avait - there was → il y avait beaucoup de monde - it was packed/very busy
Note that il y a is a useful set phrase for describing situations. It means there is/there are in the present tense. Here it is used in its past form - il y avait.
You may also use faire:
- je faisais - I used to do
- il faisait - it was (usually for the weather)
You will also use aller: