Of California's 6.3 million public school students in 2006-07, 1.6 million (25%) were considered English learners (EL). Although the vast majority of ELs in the state are Spanish-speaking, more than 50 languages are represented in the state's EL population. English learners are distributed throughout the state and across grade levels, with the highest concentration of EL students in the lowest grade levels. This report describes the state's English learners with respect to their primary languages, distribution across the grades, and location in California. It also discusses variations in English proficiency and progress toward proficiency, including how it is defined in one county that represents the state's diversity. Finally, the report considers how well these students are meeting the state's rigorous academic standards by describing their achievement levels on the California Standards Tests in English language arts and math and on the California High School Exit Exam. (Contains 17 figures.)