The imperfect (eu falava) is used to express an action that was happening in the past, in a continuous manner, as well as for repeated or habitual past actions. It is also used to describe the background of a story being narrated. It is not was well defined in terms of time as the preterite.
Eu falava can be I was speaking, or I used to speak.
Eu falava com o professor até o telefone tocar. [ I was talking to the teacher until the phone rang. ]
Let’s look at some other examples:
- Eu falava com Alessandro todos os dias. [ I used to speak to Alessandro every day.]
- Nós líamos quando Mat chegou. [ We were reading when Mat arrived. ]
- Aonde ia o senhor quando o vi? [ Where were you going when I saw you? ]
- Quando eu era criança, eu não gostava de ir à escola. [ When I was a child, I did not like to go to school. ]
- Meu marido nadava todos os dias, mas agora não pode pois está frio. [ My husband used to swim everyday, but now he can't since it is cold.] (It was a habit, but now he does not).
- Os senhores vivíam no Rio de Janeiro. [ The men used to live in Rio. ]
- Havia muita gente na festa. [ There were a lot of people at the party. ]
- O livro estava na mesa. [ The book was on the table. ]
With many thanks to my collaborator: Mat Pestana