The research reported here was carried out to help establish the normal course of fricative acquisition as a basis for comparisons with abnormal development. Three questions concerning phonological processes were investigated as part of a larger study of fricative acquisition: (1) the phonological processes that underlie children's fricative substitutions and omissions; (2) processes that are most widespread in fricative acquisition; and (3) whether or not processes are gradually limited and suppressed during acquisition. The subjects for the study were six monolingual English-learning children, four boys and two girls, who were between the ages of 1.5 and 2.3 when data collection began; all were from similar middle-class backgrounds. Five word positions were considered in analysis of the data: initial prevocalic, initial preconsonantal, intervocalic, final post-vocalic, and final postconsonantal. This study shows two areas in which current models of phonological acquisition are inadequate; specifically the indication of how many processes apply in normal acquisition or which processes are most widespread, and an account of the variable nature of process application. (AMH)