Taking as a premise that phonological working memory (PWM) affects later language evolution, in their keynote article, Pierce, Genesee, Delcenserie, and Morgan try to specify the relations between early language input and the development of PWM in terms of separable influences of timing, quantity, and quality of early language input. This paper agrees that previous work has established that PWM and language evolution reciprocally impact on one another during development (e.g., Baddeley, Gathercole, & Papagno, 1998; Gathercole, 2006; Gathercole, Hitch, Service, & Martin, 1997; Metsala & Chisolm, 2010). The aim of the keynote article was to describe how early language experience may affect the development of PWM. Pierce et al. assert that this can be done by comparing the development of PWM across groups of children with diverging language experiences during early childhood, specifically (a) delayed exposure to language, (b) impoverished language input, or (c) enriched language input. The authors propose that this comparison may contribute to establishing that individual differences in PWM are due, in part, to early language experience. Sensitive periods for phonological development that are open roughly in the first year of life are debated, and it is proposed that the quantity and quality of early language input molds the quality of phonological representations. Attempts to specify mechanisms by which early language input may affect the development of PWM have both theoretical and, potentially, clinical importance. Considering this, Pierce et al.’s article, which tries to generate a platform for future inquiry in terms of the timing, quantity, and quality of early language input, is a valuable contribution.