10.4.6 exercise6: Decide whether in these sentences the indicativo or the congiuntivo is to be used
There are some words which are used in Italian more or less the same way as in English but nevertheless their use is difficult. To this kind of verbs belongs preoccuparsi, to preoccupy oneself. One must see that ci is NOT the subject of the sentence, doesn' t rule the verb. The subject of the sentence is "che non abbia ancora scritto". In English you introduce an artificial subject in this case: It
It preoccupies us that he has not yet written.
The it references the subordinate clause "that he has not yet written". So the English and the Italian sentence is quite similar. The verbe to like / piacere is similar.
Ci piace la tua macchina.
I like your car.
It is the car that rules the verb, ci is only the indirect object. If the cars are in plural, than the verb is in plural as well, because the subject rules the verb.
Ci piacciono le tue macchine.
I like your cars.
And in this case as well a whole sentence can be the subject.