Carmen Silva-Corvalán is Professor of Spanish Linguistics in the Department of Spanish and Portuguese at the University of Southern California.

• 1. Introduction; 2. Methodology; 3. Bilingual development: a linguistic profile of the first six years; 4. Subjects in English and Spanish; 5. The order of constituents: subject position in Spanish and English; 6. The acquisition of ser, estar, and be; 7. The development of verb morphology: learning how to mark tense, aspect and mood; 8. Discussion and conclusions; Appendices: 1. Transcription instructions; 2. Calculation of MLUw; 3. Spanish adjectives used with copulas up to age 6; 4. The siblings' early verb lexicon in English and Spanish; 5. Excerpt of adapted Goldilocks story.

'Written with love, sophistication and erudition, this impressively informative longitudinal study of Silva-Corvalán's two grandchildren will become a crucial link in our current understanding of early bilingual acquisition, of key features of Spanish and of the acquisition of Spanish as a heritage language in the United States.' Silvina Montrul, University of Illinois, Urbana-Champaign

Carmen Silva-Corvalán is Professor of Spanish Linguistics in the Department of Spanish and Portuguese at the University of Southern California.

• 1. Introduction; 2. Methodology; 3. Bilingual development: a linguistic profile of the first six years; 4. Subjects in English and Spanish; 5. The order of constituents: subject position in Spanish and English; 6. The acquisition of ser, estar, and be; 7. The development of verb morphology: learning how to mark tense, aspect and mood; 8. Discussion and conclusions; Appendices: 1. Transcription instructions; 2. Calculation of MLUw; 3. Spanish adjectives used with copulas up to age 6; 4. The siblings' early verb lexicon in English and Spanish; 5. Excerpt of adapted Goldilocks story.

'Written with love, sophistication and erudition, this impressively informative longitudinal study of Silva-Corvalán's two grandchildren will become a crucial link in our current understanding of early bilingual acquisition, of key features of Spanish and of the acquisition of Spanish as a heritage language in the United States.' Silvina Montrul, University of Illinois, Urbana-Champaign

Carmen Silva-Corvalán is Professor of Spanish Linguistics in the Department of Spanish and Portuguese at the University of Southern California.

• 1. Introduction; 2. Methodology; 3. Bilingual development: a linguistic profile of the first six years; 4. Subjects in English and Spanish; 5. The order of constituents: subject position in Spanish and English; 6. The acquisition of ser, estar, and be; 7. The development of verb morphology: learning how to mark tense, aspect and mood; 8. Discussion and conclusions; Appendices: 1. Transcription instructions; 2. Calculation of MLUw; 3. Spanish adjectives used with copulas up to age 6; 4. The siblings' early verb lexicon in English and Spanish; 5. Excerpt of adapted Goldilocks story.

'Written with love, sophistication and erudition, this impressively informative longitudinal study of Silva-Corvalán's two grandchildren will become a crucial link in our current understanding of early bilingual acquisition, of key features of Spanish and of the acquisition of Spanish as a heritage language in the United States.' Silvina Montrul, University of Illinois, Urbana-Champaign