This study considered the efficacy of a differentiated approach to vocabulary instruction for learners with word-finding difficulties (WFD) in the speech and language pathologist's room. Using a pretest-posttest design to study treatment outcomes, 10 second graders with WFD received first semantic-based vocabulary instruction (S) and then semantic- and phonological-based vocabulary instruction (S & P). The S instruction focused on teaching only the semantic properties of words, whereas the S & P vocabulary instruction focused on teaching both semantic and phonological properties of words. Lexical factors of words taught were studied in reference to their influence on vocabulary instruction. Greater expressive language normalized gains were revealed for learners with WFD following the S & P approach to instruction as compared to the S approach. Phonotactic probability influenced success; learners found words consisting of common phoneme sequences easier to learn. Thus, for learners with WFD, expressive language learning was enhanced when form-based strategies were added to the semantic-based teaching paradigm. (Contains 1 table.)