This paper provides a review of past research on children's acquisition of sociolinguistic variation and the impact that variable input has on the acquisition of grammatical morphology. I describe findings from both corpus studies and experimental studies, focusing primarily on the acquisition of variably produced plural morphology and subject-verb agreement. I make two predictions: (i) variable input impacts the time course of acquisition, such that variably produced morphology takes longer to acquire than non-variably produced morphology. And, (ii) variable input does not impact patterns of acquisition. Regardless of input-type, children pass through the same developmental linguistic stages.