During the last thirty years, developmental psychology have documented the surprising speed and robustness with which babies learn the linguistics and social characteristics of their maternal environment. During the first year alone, infants achieve impressive landmarks regarding three key language components (see Figure 1). First, they tune into the phonemic categories (consonants and vowels) of their language, i.e., they lose the ability to distinguish some fine phonetic contrasts that belong to the same category, enhance their ability to distinguish some between-category contrasts, and refine their ability to ignore acoustic variations due to speaker characteristics. Second, infants refine their ability to segment the speech stream, from large prosodic units to small ones, and determine the suprasegmental features that are relevant for word recognition. Third, infants start to extract very frequent word patterns from their environnment, and compile segmentation strategies that help them constructing a recognition lexicon. These aspects of language are learned efforlessly even through they are difficult for adults to learn later in life. Moroever, they are learned without direct parental supervision. Finally, and most suprisingly, the acquisition of these three components is not done sequentially, but in a largely overlapping fashion.