P 1 : Mrm / Sjs P 2 : Mrm / Sjs Qc : Mrm

The acquisition of word classes and their distinctions has long attracted researchers of language, and Ruth Berman’s contribution to this topic has played an important role in first language acquisition literature (Berman 1985, 1986, and particularly 1988).1 This paper examines the knowledge of word classes under incomplete acquisition, a previously uninvestigated area of inquiry. Incomplete acquisition is defined here as the acquisition of L1 by a healthy child who starts out either monolingual or dominant in L1 but switches to another language (L2) as primary before age 10.2 Such speakers, who end up controlling two or more languages but are dominant in the language they acquired later (L2), are referred to as “incomplete learners,” or alternatively, as “heritage speakers” (Valdés, 2000).3