In order to build intricate language from perceptual input, children must have access to a powerful information processing system that can assay, store, and employ regularities in the signal to which the child is exposed. This paper presents that one of the most important parts of this underlying machinery is the linked set of cognitive and language processing components that cover the child's evolving working memory (WM). To explore this hypothesis, it examines how variations in the timing, quality, and quantity of language input during the earliest stages of evolution are linked to variations in WM, particularly phonological WM (PWM), and in turn language learning outcomes. In order to tease apart the relationships between early language experience, WM, and language evolution, this paper revises research findings from studies of groups of language learners who clearly diverge with respect to these aspects of input. Specifically, it regards the evolution of PWM in children with delayed exposure to language, that is, children born profoundly deaf and exposed to oral language after cochlear implantation and internationally adopted children who have delayed exposed to the adoption language; children who meet with impoverished language input, that is, children who meet with early bouts of otitis media and signing deaf children born to nonsigning hearing parents; and children with enriched early language input, that is, concurrent bilinguals and second language learners.