Doctor in filologie (1976, Limbajul poetic eminescian). Lucrari de specialitate publicate: Structura gramaticala a limbii romane. Verbul, Junimea, Iasi, 1976; Structura gramaticala a limbii romane. Sintaxa, Junimea, Iasi, 1983; Structura gramaticala a limbii romane. Numele si pronumele. Adverbul, Junimea, Iasi, 1987; Structura stilistica a limbii romane contemporane, Editura Stiintifica si Enciclopedica, Bucuresti, 1986; Limbajul poetic eminescian, Junimea, Iasi, 1979; Introducere in stilistica, Polirom, Iasi, 1999.
La Editura Polirom a publicat: Gramatica limbii romane (2001; editia a II-a, 2004; editia a III-a revazuta, 2008) si Introducere in stilistica si poetica (1999).