I am not sure of this, but i think in cases in which the pronoun subject is the same in both clauses, we would build the sentence this way: "Che cosa credi di stare facendo?". So, since this is not the way the sentence given is built we would deduce the second pronoun is different from the first.
Wouldn't "che cosa credi di stare facendo?" translate to "what do you think you are doing?" The subjunctive imperfect tense from the second example was replaced with infinitive which doesn't supply any tense, so I would expect you would have to change "credi" to "credevi" to keep the imperfect tense... Though I feel like even then the subjunctive mood is lost... would it be "che cosa credessi di stare facendo" or "che cosa credi di stessi fascendo"???
Man, italian is very confusing.
AFAIK "stare facendo" is not present. "io sto facendo" is in the present tense of the indicative mood, "io stia facendo" is in the present tense of the subjunctive mood, "io stessi facendo" is in the imperfect tense of the subjunctive mood and "stare facendo" is an infinitive form.
Imperfect Subjunctive = past tense subjunctive just like Indicative Imperfect. Here, stare is ste-ssi which can be I was (doing gerund of fare) or you were (doing). DL choose I was and so two different subjects : You then I. Had they been the same : You then You : There is a list of conjunctions that always require the subjunctive and there are four that take the subjunctive when the subjects are different. When the same they then take the infinitive , as pointed out previously, as Prima di instead of Prima che = this conjunction means before (somebody's action). Rule is when different subjects Prima che and dependent clause requires subjunctive. When same subjects use Prima di followed by infinitive. Same with senza che = without (somebody's action) : different subjects dependent clause requires subjunctive. Same subjects : senza only followed by infinitive.(no di) Perche' and affinche' both mean so that as conjunction. When different subjects dependent clause requires subjunctive. When same subjects drop Perche' and Affinche' and substitute Per followed by infinitive. Note: double infinitive , the first can drop its "e" - but the infinitive can drop its "e" followed by any word. The other conjunctions that require subjunctive always use subjunctive regardless of subjects. These ,as well as verbs and expressions , that require the subjunctive I hope to list at some time.
Credere means both to believe and to think and several other things, see http://www.wordreference.com/iten/credere. Also there is a very helpful discussion on usage of credere here, http://forum.wordreference.com/showthread.php?t=486821&langid=14
That wordreference discussion under-delivers a bit. But somewhere out there in the great big internet, there must be a good list of Italian phrases that English speakers tend to get wrong. Some day I will find it.
In wordreference, the Collins tab can be very helpful to intermediate learners since it provides example phrases. Also I recently found reverse.net, see http://context.reverso.net/translation/italian-english/cosa+credi+che.
Not exactly; more like "I was". It's the imperfect first person form of the verb "stare"; that is (in this context at least) "to be". (Not to be confused of course with essere which also means "to be", just not quite in the same way. The distinction between these two is arguably the most brain-exploding concept for English speakers to try to get their heads around in their early to middle days in Italian, though it's slowly starting to feel more natural.) Facendo is obviously the gerund form of fare ("to do"). In English, it's the equivalent of "doing". But the question is... who was doing that "doing". The answer is that I was; that is, "stessi (I was) facendo (doing (it))". (I put the "it" in brackets because obviously that comes from the preceding "che", it's just easier to explain if I include it.) Combining the imperfect form of Stare with the gerund of another noun gives you the equivalent of a past progressive tense in English; that is, something that was a continuing action in the past. (In this case. "(what) I was doing".) Like many things in Italian or any other language it will only start to feel natural when you use it enough, and don't have to break it down into gramatical rules as I've done here, but knowing the underlying reason of why expressions are as they are isn't necessarily a bad thing.
The conjugation table shows: first person single imperfect subjunctive of stare.
Also you can refer to wiktionary.
Well, you don't. Like the 3 singular persons in the present subjunctive, they're all alike: as a general rule you should make the subject known, but on a practical level many don't (hence the "general"). It can cause some misunderstandings and subsequent needed clarifying. To avoid all of that, always clarify who's the subject. I don't even understand why it's not an established sound rule, bah.
I agree, but in general it works best to assume that first person was intended unless the context or the presence of a subject pronoun makes it obvious that second or third person was intended. In fact, Italians often insert the subject pronoun if it is anything other than "io".
Yes, generally the "io" wouldn't be expressed but still, it really depends om the situation. In order to avoid any ambiguity or misunderstanding I'd just say to specify it in cases like this. Let's not make grammar unnecessarily harder, it already is what it is and there's no need to remember supplementary things at this stage.