Sorprenderse vs Estar Sorprendido

Question

The title of my question is only an example of several variations I've found on the same theme: when to use reflexive and when to use estar+participle?

Me sorprendí cuando me propuso matrimonio

Estaba sorprendida cuando me propuso matrimonio

It seems to me that the reflexive above suggests more of an action (it surprised me...), while estar+participle suggests a state (being in a state of surprise).

Could you explain and demonstrate by example how one might be chosen over the other?

Also, the reflexive seems to be prompting me to add que+subjunctive (Me sorprendí que me propusiera matrimonio), but the participle version does not.

As you see, I'm a little confused and I wonder if my confusion comes from learning Latin American Spanish? The participle seems to occur more often when I read that variant.

Saludos a todos

Accepted Answer

Hola GraemeThe meaning is pretty much the same but the syntax is different.1. Me sorprende que Juan me proponga matrimonio.Subject: "que Juan me proponga matrimonio" (= algo)Verb: sorprende (agreeing with the subject)Indirect Object pronoun : me(=algo me sorprende)2. Me sorprendo de que Juan me proponga matrimonio. Subject: Yo Verb: me sorprendo (reflexive)Subordinate clause: de que Juan me proponga matrimonio (this type of subordinate clause in Spanish is called "subordinada sustantiva de complemento preposicional")So the difference is basically the different uses of the verb "sorprender", but the meaning is the same.I hope this helps,Inma

Answer

Hola Graeme
You are right at thinking that the verb conjugated talks about the action while the use of estar +participle talks about a "result" (so something, an action, happens and then someone is/stays surprised.) 
So you would simply chose "me sorprende que..." when you want to express the action/progress of something surprising you, e.g. "me sorprende que Juan me proponga matrimonio", and then when that proposal has already happened you would probably say "Estoy sorprendida de que Juan me haya propuesto matrimonio", or maybe this last one would sound better splitted into two more independent clauses, something like:
Juan me ha propuesto matrimonio y, la verdad, estoy sorprendida.
In terms of using the subjunctive, you would normally use it with the verb sorprender as in "something surprises someone" or as a reflexive verb "you get surprised by something", so:

Me sorprende su actitud.
Me sorprende que Juan me proponga matrimonio.
Me sorprendo de que Juan me proponga matrimonio. 
Me sorprendí de que Juan me propusiera matrimonio.

Bear in mind we use "de que" when it is used as a reflexive verb "sorprenderse de algo".
If you use "estar + participle" + de que + clause, you would still use the subjunctive, because it is still a structure expressing an emotion, the same way some other verbs do, e.g. "me encanta que me haya propuesto matrimonio", "me hace feliz que me haya propuesto matrimonio"..., so:

Estoy sorprendida de que Juan me haya propuesto matrimonio"
Estaba sorprendida de que Juan me hubiera propuesto matrimonio.

To sound natural with the indicative it'd be better to use these structures with other type of subordinate clauses:

Me sorprendí cuando Juan me propuso matrimonio. 
Estoy sorprendida por el hecho de que Juan me ha propuesto matrimonio.

I hope this is useful.
Saludos cordiales 
Inma

Answer

Thanks Inma, yes that's very useful!

However, it has raised another, somewhat off-topic, question. What's the difference between these two?

Me sorprende que Juan me proponga matrimonio.

Me sorprendo de que Juan me proponga matrimonio.

Saludos