The production of word stress in a second language (L2) is one area of difficulty for language learners. Previous studies have shown that correct word stress may be more important for the comprehensibility of non-native speech than grammatical accuracy. Studies indicate that incorrect stress patterns in an L2 are mainly due to transfer from learners’ first language (L1). This thesis examines the effect of training on the ability of English native speakers who are beginner-level learners of German to produce stress patterns in words from three distinct categories: native German words; German-English cognate words; and words with unstressed suffixes. The results reveal that training improves learners’ production of German word stress and raises learners’ awareness. Participants were more accurate in their production of native German words and those with unstressed suffixes than they were in their production of cognates. The results have implications for vocabulary teaching in L2 classrooms.