The authors address instruction in morphological analysis, a vocabulary-learning approach that involves teaching students the meanings of affixes (prefixes and suffixes) and word roots and a strategy for using knowledge of these morphemic elements to infer the meanings of unfamiliar words. The authors discuss their development of a list of affixes and word roots for instruction in grades 3-5, share this list, and provide guidelines for using it in elementary classrooms. The authors then describe four instructional activities that constitute the multidimensional approach to affix instruction that they designed through researcher-teacher collaboration and that produced robust student learning.