ABSTRACT
One invaluable source of information about what children know, consists of observations of their spontaneous speech, whether in the form of daily diary entries or regular recording sessions that are then transcribed. Numerous researchers have kept detailed, often daily observations of what their children say and how they say it. Among these diarists are several who have looked at various aspects of word formation (e.g., Berman & Sagi, 1981; Bowerman, 1977, 1982; Clark, 1982, 1993; Stern & Stern, 1928).
