In a present context, the imperfect refers to an earlier speech:
You thought I didn’t know it, right? ¿Creías que no lo sabía, eh?
When you want to give advice
– Deberías correr mas (You should run more)
– Tendrías que comer mas (You should eat more)
– Mainly is deberias and tendrias, there is not much ways to give an advice
Polite way of asking something
Quería un paquete de cigarrillos por favor? (I wanted a package of cigarettes please?)
Necesitaba un paquete de cigarillos por favor? (I needed a package of cigarettes please?)
Estaba interesada en el departamento publicado en craigslist. ( I was interested in the apt published on craigslist)
These are expresions to ask in a polite way what you want, need or were you interested in. This is different than English, but we use it in Spanish.
To express a wish in a future context
Ahora mismo me iba da vacaciones. (Right now I was going on vacation)
Ahora me estaba yendo a trabajar. (Ritht now I was going to work)
Ahora estaba por sacar al perro (Right now I was going to take the dog for a walk)
These are ways to express the future with the imperfect. Doesn’t exist in English, but in Spanish YES, we use these expressions.
Yo que vos/tu lo compraba en Victoria Secret. (If I were you I would have bought in Victoria Secret)
Yo que tu/vos me iba a el Caribe. (If I were you I would have gone to the Caribean ocean)
Yo que vos le pedía perdon a Juan. ( If I were you I would have said sorry to Juan)
When you want to express what other people said:
El dijo que quieria ir al cine. (He said he wanted to go to the theater)
Ella dijo que ellos no eran de confiar. (She said that they weren’t people to trust)
Nosotros dijimos que nos íbamos a casar por iglesia. (We said that we were going to get married by church)