Teachers can learn about the sounds, spelling systems, and other structural features of students' first languages from a variety of sources. Learner English, by Michael Swan and Bernard Smith, contrasts English with a number of other languages. Teachers can also ask bilingual or ESL teachers who may have specific knowledge about languages other than English—although it is certainly true that native speakers have not necessarily studied the structure of their first languages. Finally, teachers can engage older students in finding out more about their first language. As a class, teachers and students can investigate the sounds, spelling systems, and structure of English and other languages. Knowledge about contrasting language systems can help teachers understand students' problems with literacy and tailor instruction not only to what students don't know but also to what they do know.   next