hablaba is past tense, hablaré is future

Hablé means I spoke, it is as simple as that. Example: Ayer hablé con el( I spoke with him yesterday) It is also used when you are refering to a call. Ayer te hablé por telefono( I called you yesterday) Tough the word for call is -llamar-(llamé in past) both are commonly used but if you use -hablé- you must specify it was on the phone with the phrase-por teléfono-or specify why you talked. Hablaba- means two things depending on the use. 1.I was talking ( at specific time) 2.I used to speak. Example: Ayer hablaba con el....(I was speaking with him)-Note this is similar to the one above but in this one you can't let the phrase like that you must tell what happens next. Example 2: Cuando era un bebe hablaba gracioso( When i was a baby i used to speak funny) So any verb with the termination ABA means something you did a while ago or in the past, something you used to do. i'll give you some examples: Yo jugaba base ball-I used to play base ball Hoy jugue base ball-I played base ball today Tocaba la guitarra ayer-I was playing guitar yesterday Toque la guitarra ayer- I played guitar yesterday Trataba de entender pero no podía- I was trying to understand but i couldn't Trate de entender pero no pude-I tried to understand but i couldn't . Note the verb poder don't have the termination aba but ía , a lot of verbs use the termination ía instead of aba. Example: Veía,sentía,dormía,comía,corría, salía etc etc. Now with the phrase.Preguntó mientras devoraba means He asked while he was devouring ... Preguntaba mientras devoro means , He was asking while he devoured*... As you can see the second one don't make sense because you can't say devoró until he finished devouring.Preguntaba could also mean he was asking constantly.

Devoraba is a simultaneous action. You can see that both things are happening at the same time. Preguntó mientras devoraba la comida que yo le había preparado = He asked while devouring the food I had prepared for him Preguntó = He asked Mientras devoraba la comida = While devouring the food The thing is you need to think of the complete structure, not only the verb "devoraba" . I hope it helps. =) My sister told me about the accident while crying = Mi hermana me contó sobre el accidente mientras lloraba"

I dont undestand your question completely. "Hablaba" is similar to "estaba hablando" (I was talking). Yo hablaba con Juan cuando empezó a llover = yo estaba hablando con Juan cuando empezó a llover. It is used for a continuous action: Juan hablaba mucho = Juan era muy hablador The action of "hablé" is finished. Yo hablé con Juan. Después, empezó a llover Juan habló mucho = En algún momento, Juan estuvo hablando durante mucho tiempo. (One day, John spoke a lot)