As children learn language, they spontaneously imitate the speech of those around them. This article investigates the new words that five children imitated between 1 and 2 years of age. Children were more likely to imitate new words as they aged and as their productive language developed. After controlling for age, children also were more likely to imitate new words that were shorter and with high neighborhood densities, and that contained sounds the children had previously produced accurately. Together, the findings demonstrate that both the patterns of the target words and children's productive abilities are predictors of children's imitative speech. This supports models of language development where there are influences stemming not only from phonological and lexical representations, but also from phonetic representations.

Old French subject pronouns (Spro) were omissible if postverbal (Foulet 1928), but not freely so (Vance 1997, Zimmermann 2014). This article addresses their partial omissibility in discourse-syntax terms, following work on partial null subject languages by Holmberg and Nikanne (2002) and Modesto (2008). An observational study of dialogic responses in 13th century prose romances is first reported, finding strong indications of covariation between the Topic/Focus status of an initial non-subject constituent and the expression/omission of post-verbal Spro. A quantitative investigation, in such texts, of preposed discourse-linked anaphoric constituents and preposed intensifiers, taken as diagnostic of Topichood and Focushood respectively, confirmed this analysis. We take null Spro to be available (i) when a null Topic operator targets left-peripheral TopicP, and (ii) with a left-peripheral Focused expression. When a discourse-linked non-subject constituent occupies TopicP, however, Spro must be overt.

Quantity and quality of input affect language development, but input features also depend on the context of language emission. Previous research has described mother-child interactions and their impact on language development according to activity types like mealtimes, book reading, and free play. Nevertheless, few studies have sought to quantify activity types in naturalistic datasets including less-studied languages and cultures. Our research questions are the following: we ask whether regularities emerge in the distribution of activity types across languages and recordings, and whether activities have an impact on mothers' linguistic productions. We analyse input for two children per language, at three developmental levels. We distinguish three activity types: solitary, social and maintenance activities, and measure mothers' linguistic productions within each type. Video-recorded activities differ across families and developmental levels. Linguistic features of child-directed speech (CDS) also vary across activities – notably for measures of diversity and complexity – which points to complex interactions between activity and language.

The hypothesis that Old French was not a verb-second (V2) language, but rather a Topic-initial language, is evaluated in a corpus of verb initial (V1) and V2 matrix clauses extracted from a corpus of 12th- and 13th-century texts. It is shown that the initial constituent of V2 clauses is not always a Topic; it may be part of the informational Focus, or it could be an element that is neither Topic nor Focus. In addition, in V1 and V2 sentences with subject inversion, the postverbal subject may be an informational Topic, contrary to the hypothesis that subjects must move to the preverbal position to avoid being interpreted as part of the informational Focus. Therefore, from an Information-Structure point of view, Old French is similar to a standard V2 language like German. However, certain differences between 12th- and 13th-century texts could suggest that the use of the left periphery evolved during the period considered.

Naturalistic data are a useful source for language acquisition research. Recently, the emphasis has been placed on using denser corpora, in order to capture a more accurate picture of child language development. However, working with large amounts of data raises resource issues, since it is time-consuming to record and to transcribe. In this article, I focus on what would be the ideal duration of a naturalistic recording for it to be considered a representative enough sample of children's linguistic behaviours to observe the acquisition of words and sounds. Some of the results suggest that 30 minutes of recording may be enough to capture these specific developments, but these results are discussed in the perspective of what an ideal session could be.

Old French (OF) is often characterized as a Germanic-style asymmetric V2 language, although this characterization is often questioned. The present study evaluates the nature of OF V2 from a quantitative perspective. An extensive set of data provided by syntactically annotated corpora shows that both IP and CP structure change over the OF period. Focusing on Germanic inversion – XVS word order – I argue that most of the attested inversion in OF occurs within an elaborated IP structure and that this type of subject inversion dwindles over time due to the decreasing use of null expletives. True Germanic-style embedded V2 does not appear until the late 12th century, and is only rarely used throughout the 13th century. Thus, OF is an asymmetric V2 language, but with a difference, namely in having an IP field that allows for apparent V2 orders and a CP field that is only marginally employed.