ABSTRACT
Children sometimes make an adult pattern of non-distinctive or optional morphophonemic alternation more regular or invariable than it is in the adult model. Examples of this are the observed patterns of realization observed for nasals in phrase-final position and for phrase-final laterals. For the nasals, in fact, it is possible that some of the children remained uncertain of the "correct" underlying form for some nasal-final roots. Contrary to common supposition, younger children are not more sensitive to phonetic deviance than are older children. Older children made more successful and more flexible attempts to imitate exotic segments than did younger ones, in many cases. Children's productions will honor morpheme-structure constraints increasingly with age even when these productions are not identifiable as meaningful forms in the language being learned. Children's difficulties with tonality in vowels may be due to an inherent analytic difficulty whereby more than one possible set of distinctive-feature definitions emerges in different children.
