Réponse:

1) was

2) is working

3) went

4) I'm reading

5) were

6) they went - when he was

7) Did you watch

8) had

9) is living

10) did you paint it?

11) I didn't see

12) wrote

Explications:

Preterit=une action passée (=passé composé ou imparfait en français)

Be+ing=une action encore en cours