This paper addresses the emergence of complex syllables with coda consonant (r) in the acquisition of Brazilian Portuguese in the speech community of Rio de Janeiro. Acquisition of words containing complex syllabic types implies the diminishment or abandonment of the CV pattern, but what happen when the competing variable forms alternate different syllable shapes? Since variants are competing forms of the same word, in some cases, they also reflect competing phonological patterns and sociophonetic variation plays a role in abstracting mental representation. Studies about the speech community showed that the coda is variably realized alternating a phonetic velar/glottal variant with its absence and that internal codas are much more realized than final ones (Callou, 1987; Votre, 1978). There is no stigma related to the zero variant in final coda (noun and verbs). The study is based on a cross-sectional sample of 11 typically-developing children (from high and low middle class) distributed in age levels but not in relation to gender or class. The age grading ranges from 2;1 to 5;0. The analysis showed different distributions of frequency of variants as a reflex of the structured variation observed in the speech community. The results reveal that (r) is almost categorically absent in final verbs in all age levels, which can be taken as evidence that children are developing the CV pattern as the main representation of infinitives. Children’s behavior for medial codas is more consistent with a CV(r) pattern as the central representation than word final coda in all ages. The results obtained in this study for final verb coda is consistent with a final stage of a change in the direction of the loss of the infinitive morpheme in the speech community.