The PROCEEDINGS OF THE THIRTIETH CHILD LANGUAGE RESEARCH FORUM makes an empirical, as well as a theoretical, contribution to linguistic research. The contributors to the Proceedings of the Thirtieth meeting explore their findings on language acquisition in a variety of the world's languages, reflecting the diversity of interests in the field and the range of languages being studied. Topics examined in this volume include the difficulties experienced by a bilingual child, the difference between the rhythmic characteristics of children compared to adults, and children's ability to learn inflectional agreement from parental speech. The studies included in this volume were presented at the 30th Child Language Research Forum held at Stanford University in 1999. Since its inception in 1967, the Forum has provided an informal but critical setting for the presentation of new ideas and research on first language acquisition. The Forum itself is sponsored by the Linguistics Department at Stanford University, and is organized by graduate students. The Forum draws researchers from around the globe. The papers presented at the Forum reflect the diversity of interests in the field and the range of languages being studied.