I was just wondering...
Acabo de preguntarme
or
Me preguntaba
What do you think?
3 Answers
"Me preguntaba" is correct. "Acabo de preguntarme" means " I just asked myself".
"Yo preguntaba" means "I used to ask".
Alexengijon commented
Hmm yes, but wondering is asking yourself
I think this may miss the point that Gekkosan was trying to make. Your original question asked whether the following would be correct
I was just wondering... ? Acabo de preguntarme...
However, by your response it seems that the semantic value of the word "just" may have gotten confused. It should be noted that in English, the use of the adverb "just" can be a bit ambiguous.
Using "just" as an adverb of time
In your attempted Spanish translation, the expression "acabar de + infinitivo" can be translated to say that you just did something, but the use of the word "just" is in the sense that you just (very recently, a very short time ago) completed or finished an action. In this case, "I was just asking myself (about that)" or "I was just wondering (the very same thing)" might be reasonable translations. It should be noted, however, that used this way, it is usually as a response to something someone has said (i.e. "I was just wondering the very same thing" or "I was just asking myself that very question.").
Using "just" as an adverb of degree
On the other hand, it is probably much more common to consider "I was just wondering..." as a commonly used set expression where the word "just" carries a different semantic value than in the previous example. Instead of using the adverb, "just" as an adverb of time, it is often used in this type of expression as an adverb of degree which is roughly the equivalent of saying something like "I was only wondering," "I was merely wondering" or "I was no more than wondering." In this sense, it would not be possible to use the expression, "acabo de," and instead you would probably need to say something like, "solamente me preguntaba..."
Yo preguntaba