The imperfect subjunctive will has the same irregularities as the preterit form of the verb. Let's look at some examples:

El profesor quería que yo hiciera la tarea anoche.
The teacher wanted me to do the homework last night.

Fue interesante que dijeras eso.
It was interesting you said that.

Tú te saliste como si tuvieras mucha prisa.
You left as if you were in a big hurry.

¡Qué pena que estuvieras enfermo todavía!
What a shame (it would have been) if you were still sick!

María esperaba que nosotros fuéramos al cine con ella esta tarde.
Mary was hoping that we would go to the movies with her this afternoon.

Yo esperaba que tú fueras a la tienda conmigo.
I was hoping that you would go to the store with me.