Cross-linguistic research on the development of tense-aspect marking has revealed a strong effect of lexical aspect. But the degree of this effect varies across languages. Explanation for this universal tendency and language-specific variation is still an open issue. This study investigates the early emergence and subsequent development of four…

The relation of social and linguistic input measures to early vocabulary development was examined in 30 low-income African American mother-infant pairs. Observations were conducted when the child was 0 years, 1 month (0;1), 0;4, 0;8, 1;0, 1;6, and 2;0. Maternal input was coded for word types and tokens, contingent responsiveness, and…