The foundations for language acquisition, arguably our most quintessential human achievement, are in place by birth. As will be reviewed in this talk, there is specialization in the human brain from birth for processing language and for learning its properties. Yet already by birth the infant’s brain has started becoming attuned to the properties of the native language, and this attunement accelerates over the coming weeks and months. The timing of attunement to different properties of the native language unfolds in a sequential manner, and in most circumstances seems to be tightly constrained by maturation. However, there are identifiable experiential conditions and types of exposure that accelerate and/or delay the timing of attunement. This complex interplay between biological preparedness and experiential influences will be the topic of my presentation. To illustrate this theme, a series of recent studies on the effects of experience on speech perception will be presented, including studies of perception in fetuses of 36 weeks gestation and up to word learning toward the end of the first year of life.