Two lawful relationships involving word-initial onset clusters have been advanced in the acquisition literature; namely, that clusters imply affricates, and that liquid clusters imply a liquid distinction. This study evaluated and extended the validity of these implicational laws in a population of 110 children (aged 3;0 to 8;6) with functional phonological delays who contributed extended speech samples for computational analyses. Results indicated that, for the most part, the composition of children's sound systems were in compliance with the proposed laws; however, there were noted asymmetries and apparent exceptions in the data. The asymmetries motivated an integration of the two laws to reveal a pattern of segmental–prosodic cyclicity consistent with deterministic models of phonological acquisition. The apparent exceptions highlighted the relevance of independent methodologies and offered a potential theoretical alternative with the Resolvability Principle as directions for future research.