He has led research about Italian linguistic history from the Middle Ages[2][3] to the present day.
[4] He has authored Il Devoto-Oli dei sinonimi e contrari, a dictionary of synonyms and antonyms published by Le Monnier in 2013.
[5][6] Together with Luca Serianni he is in charge of the Vocabolario della lingua Italiana Il Devoto-Oli.
[7][8] From 2000 to 2005 he was director of the Language Centre at the Foreigners University of Siena and he held training courses for Italian teachers in many countries around the world.
He has created Affresco Italiano, an Italian language course for foreigners in 6 volumes (from A1 to C2 levels).