In most cases, structured English immersion (SEI) has replaced bilingual and English as a second language (ESL) programs as the preferred method of educating English language learners (ELLs). As a result, science teachers need specific strategies to develop language skills along with content. One suitable technique for and used by teachers is the mode continuum (Gibbons 2002), a process that leads students from speaking about science to writing about science. This chapter describes the four phases of the mode continuum strategy and provides an example of how it was used to effectively meet the needs of an ELL student.