"Radical" templatic phonology is a template-based approach to segmental phonological representation. The central hypothesis is that the segmental phonological structure of words is represented as language-specific phonotactic templates, in the sense used in the developmental literature. Template-based organization of the early lexicon has been identified in children acquiring several different languages. It is the result of a usage-based abstracting or "induction" process based on both babbling practice (phonetic production) and input experience with specific adult phonological patterns. The resulting templates thus constitute patterns that reconcile (or 11 adapt") the model provided by target words with the child's own phonetic repertoire of syllables or word shapes - typically extending or building on the forms initially "selected" for first word production, in which adult and child forms show a close match. In adult phonology segment categories natural classes, or features - are best defined in terms of their occurrence in positions in the templates in individual languages, not as independent universal categories. After reviewing the status of segment categories and their phonetic basis in contemporary phonological theory we present crosslinguistic evidence of pervasive variation in both phonetic realization and phonological distribution patterns, evidence that supports the template construct

The emergence of features plays a key role in any theory of phonological development that does not assume that they are innately available before the onset of speech. After reviewing Jakobson’s claims for universal orders of emergence, we consider possible criteria for feature or segment acquisition, and then discuss data from nearly 50 children (10 languages including Estonian, Finnish, Japanese, and Welsh as well as several Germanic and Romance languages). Small early vocabularies and phonetic variability make minimal pairs rare in most children. While a few children show clear evidence of utilizing features or segments, others show none, and most fall between these extremes. Gradually increasing evidence of segmental structure and systematicity reflects the slow transition to a more orderly phonology. These data support an emergentist model of feature acquisition that has many possible routes to (re-)creating phonological organization within the individual child’s mind.

Children raised in the home as English or Welsh monolinguals or English–Welsh bilinguals were tested on untrained word form recognition using both behavioral and neurophysiological procedures. Behavioral measures confirmed the onset of a familiarity effect at 11 months in English but failed to identify it in monolingual Welsh infants between 9 and 12 months. In the neurophysiological procedure the familiarity effect was detected as early as 10 months in English but did not reach significance in monolingual Welsh. Bilingual children showed word form familiarity effects by 11 months in both languages and also revealed an online time course for word recognition that combined effects found for monolingual English and Welsh. To account for the findings, accentual, grammatical, and sociolinguistic differences between English and Welsh are considered.