questo = comes before a noun that is singular and masculine. Questo libro e' interessante. = This book is interesting. questa = comes before a noun that is singular and femine. Questa lettera e' per Lei. = This letter is for you. questi = comes before a noun that is plural and masculine. Leggiamo questi libri. = We read these books. queste = comes before a noun that is plural and femine. Queste donne dormono troppo. = These women sleep too much. quest' = comes before a singular noun that begins with a vowel. Chi e' quest'uomo? = Who is this man? Mi piace quest'arancia. = I like this orange.