The first part of these findings is a report on a study of the characteristics of 120 Spanish-English bilingual children's speech over a two-year period in the classroom, on the playground, and at home. Three types of language measures were used as well as audiotaped speech samples taken in the three communication settings. Preliminary findings suggest that (1) children vary in language usage and preference depending on the setting; (2) discourse in the classroom is predominantly English; (3) acquisition of reading skills and of language is individualistic in nature; (4) codeswitching is more prevalent in some communities than others; and (5) multiple measures of oral language proficiency may be needed for valid assessment. The second part of the report focused on the bilingual discourse of 24 children in kindergarten through grade two, using utterance as the basic unit of speech. The analysis examined: (1) frequency of codeswitching in two different border areas in Texas; (2) codeswitching over a period of two years; (3) language mixing as a function of age/grade level; and (4) type of language mixing over time and by region. It was found that codeswitching did not occur with great frequency, and that regional differences were found in the extent to which it did occur. (AMH)