Estuve o estaba + gerundio

[agatita]

Hiya,
I've got a question. I don't know the difference between estuve y estaba? for example these three sentecnes :

1) Estuve escribieno una carta para mi amiga.

2) Estaba escribiendo una cara para mi amiga.

or that option:

3) Escribía una carta para mi amiga.

well....more or less i know the difference between estuve escribiendo y estaba escribiendo. but i dont see much difference between Estaba escribiendo y escribía...Could anyone explain it to me?

thanks

[laepelba]

I'd love to hear the answer to this, too.

In fact, I'd add a fourth option:
4) Escribí una carta para mi amiga.

[Rusty]

estar + gerundio (estar escribiendo)
This structure is the progressive. This is used to describe action that is in progress (I was in the very process of writing, for example). Take care to not overuse this verb form; if you are not in the very process of writing something, choose the indicative mood instead.

estaba + gerundio (estaba escribiendo)
I was in the process of doing something when I was interrupted by something else. After the interruption, I returned to what I was doing.

estuve + gerundio (estuve escribiendo)
I was in the process of doing something when I was interrupted by something else. I did not return to that activity after the interruption.

imperfect indicative (escribía)
I was doing something. Indicates a setting of the stage for another event, a habitual action, or a repetitive action.

preterite indicative (escribí)
I did something. The action had a start and an end in the past.

[laepelba]

Thanks, Rusty. If I work with these constructions enough, I'll get them.... (Thanks for the question, Agatita!!)

[tacuba]

Originally Posted by laepelba

Thanks, Rusty. If I work with these constructions enough, I'll get them.... (Thanks for the question, Agatita!!)

Some examples:

Escribía una carta y me cayeron unos amigos.
I was writing a letter and some friends dropped in on me.

Escribí una carta a mi amiga ayer.
I wrote a letter to my friend yesterday.

[literacola]

Originally Posted by Rusty

estar + gerundio (estar escribiendo)
This structure is the progressive. This is used to describe action that is in progress (I was in the very process of writing, for example). Take care to not overuse this verb form; if you are not in the very process of writing something, choose the indicative mood instead.

estaba + gerundio (estaba escribiendo)
I was in the process of doing something when I was interrupted by something else. After the interruption, I returned to what I was doing.

estuve + gerundio (estuve escribiendo)
I was in the process of doing something when I was interrupted by something else. I did not return to that activity after the interruption.

imperfect indicative (escribía)
I was doing something. Indicates a setting of the stage for another event, a habitual action, or a repetitive action.

preterite indicative (escribí)
I did something. The action had a start and an end in the past.

I don't understand why estaba + gerundio would ever be used over the imperfect. Is it just that the subject returned to what they were doing?

[Sancho Panther]

Originally Posted by tacuba

Some examples:

Escribía una carta y me cayeron unos amigos.
I was writing a letter and some friends dropped in on me.

Escribí una carta a mi amiga ayer.
I wrote a letter to my friend yesterday.

I'm sorry I must dispute the above underlined example - to say "I was writing a letter and some friends dropped in"' you should say <Estaba escribiendo una carta cuando llegaron algunos amigos.>

The verb 'caer' is never used in the sense of 'to drop in', only as 'to drop/fall'.

The second example is fine though.

[Rusty]

Originally Posted by literacola

I don't understand why estaba + gerundio would ever be used over the imperfect. Is it just that the subject returned to what they were doing?

It's true that the imperfect tense can be used for the same situation. The progressive form only serves to give emphasis to the fact that there was an act in progress at the very second the interruption occurred.

Here are two sample sentences with a truer-to-form English translation:
Estaba comiendo cuando me llamaste.
I was in the middle of a bite when you called me. (Note the emphasis given. The progressive form emphasizes that eating was interrupted.)
Comía cuando me llamaste.
I was eating when you called me. (No emphasis - I was doing this when something else happened.)

The progressive form isn't used nearly as much in Spanish as we English speakers would like to think. (That is why I try to steer folks away from it. )
The problem lies in how similar the progressive form looks to one of our indicative forms. For example, the indicative mood, present tense, first-person form of comer is como. This can be translated into English as I do eat, I eat or I am eating. Many Spanish learning materials don't dwell on this fact, having us think that it only means I eat.
The progressive form, estoy comiendo, is often translated as I am eating, but a closer translation would be: Can't you see I'm eating here?

[Tomisimo]

This has already been mostly answered, but here's my take on this:

Imperfect - refers to actions that may or may not be completed
Estaba escribiendo una carta = I was in the act of writing a letter (and I may or may not have continued)
Escribía una carta = I was writing a letter (and I may or may not have continued)

Preterit - refers to actions that are complete or finished.
Escribí una carta = I wrote a letter (and then stopped/finished)
Estuve escribieno una carta = I was in the act of writing a letter (but then I stopped)

The difference between using the present progressive and the simple tenses is that the present progressive usually implies "in the act of" doing the action.

[tacuba]

Originally Posted by Sancho Panther

I'm sorry I must dispute the above underlined example - to say "I was writing a letter and some friends dropped in"' you should say <Estaba escribiendo una carta cuando llegaron algunos amigos.>

The verb 'caer' is never used in the sense of 'to drop in', only as 'to drop/fall'.

The second example is fine though.

Sorry Sancho, but I've heard this usage many times here (in Mexico) where I live.

From the Larousse Gran Diccionario: -21. Am (visitar) to drop in