A study of transfer of native language training and/or interference in learning English idioms had as its subjects 12 Venezuelan students in an American university who were advanced learners of English as a second language. Fifteen equivalent and commonly used English and Spanish idioms were used in tests of recognition, comprehension, recall, and production. Statistical analysis of the results indicates that the subjects were able to generalize from the idiom's meaning in Spanish to its meaning in English, even when the form was slightly different, and they could correctly produce many more identical idioms than idioms of other types. Both of these results indicate use of positive transfer. Interference (negative transfer) occurred on the two production tests, more for similar than totally different idioms. These results support the notion that advanced second language learners whose first language is closely related to the second can use knowledge of idioms in their first language to comprehend and produce idioms in the second. In addition, the subjects used target-language-related strategies such as mixing idioms and providing an incomplete idiom. It is suggested that language similarities may encourage interference, and that idioms are not always considered nontransferable. Further research is recommended. (MSE)