I did the same - it looks like it's the verb "pensare" that is causing the problem... my book says that "ci" is sometimes used to mean "it" or "about it" with certain verbs... one of those being pensare (also capire, credere?). It says that it is used when the verb would normally take "a" after it - so that's pensare again.
My question is therefore, how do you say "i had thought about them?"
Here's a fabulous video on ci and ne. I believe the way that ci works here is covered about 2 minutes and 40 seconds into the the video.
did the same mistake... but thinking it would most probably be wrong as "ci" before the auxiliary means that the past participle has to be agreed and should therefore have been "pensati" ... but still confused, I hate all those ci, cui, coi (if this one exists?) and it's frustrating not to know!
It's not so hard to understand.
Verbs without a preposition need the direct object pronoun
ringraziare qualcuno (la ringrazio)
Verbs with a preposition (normally a, di) need the indirect object pronoun
scrivere a qualcuno (le scrivo)
occuparsi di qualcosa/qualcuno
There are also some verbs that can have both:
- consigliare qualcosa a qualcuno (te lo consiglio)
I don't know why either, but I did a search on the sentence to see how Italian speakers used it in context. And the context always indicated that ci meant "it" rather than "us."
"Io le risposi che ci avevo pensato molte volte, ma da sola non era facile" (I told her that I had thought about it many times, but it was not easy on my own)
"Guarda, io sono sempre stato molto vicino alla chiesa, fin da quando ero bambino. ci avevo pensato molte volte" (Look, I've always been very close to the church since I was a child. I had thought about it many times)
"lol all'idea di un remake ci avevo pensato molte volte molto molto tempo fà." ( lol to the idea of a remake I had thought about it many times a long long time ago)
Italian verbs take many forms. 'andare'--to go, 'andarsene'--to go away; 'chiedere'--to ask, 'chiedersi'--to wonder; 'mangiare'--to eat, 'mangiarsi--to be enraged. 'pensare--to think, 'pensarci'--to consider something. this would be equivalent of 'pensare+the preposition 'a'+a noun (sto pensando alla vacance. ci sto pensando) having written all of this it's not clear to me that ci can't mean 'us'. the only reason that comes to mind is the highly idiomatic meaning of 'pensarci'--to consider it or to take care of it. here are two sites that answer this issue. http://www.dummies.com/languages/italian/conjugating-italian-verbs-with-ci/ and https://blogs.transparent.com/italian/tricky-little-words-%E2%80%9Cci%E2%80%9D/