I was wondering about the conjugation of the verb "sparire" (to disappear). I have the book "Verbi in tasca", and noticed there that, for instance the passato prossimo is "hanno sparito". But when I did a web check I noticed that far far more often the passato prossimo is given as "sono sparito". Are both acceptable? Thanks in anticipation!
Indeed, the auxiliary verb for sparire, as for most intransitive verbs, is essere (as can be checked in any real dictionary), so the passato prossimo is sono sparito, sei sparito, è sparito, siamo spariti, siete spariti, sono spariti (mind the fact that the past participle agrees for its number, singular/plural, with the subject: sparito vs. spariti).
I don't know that Verbi in tasca book, but if this is not an occasional “bug”, the book looks less than useless.