From level 100 and up, Sonlight incorporates Language Arts instruction and assignments in your studies. If your child needs additional grammar and/or vocabulary instruction, Sonlight recommends these optional workbooks. Optional Language Arts Workbooks: For use with the Sonlight 100 program. Sonlight 100 students benef Sonlight resource: https://www.sonlight.com/products/language-arts-for-sonlight-100-optional-workbooks-set