The hypothesis is examined that informal conversation with native language speakers might not be helpful for adult second language learners, because untrained native speakers have trouble modifying their speech. Conversations between pairings of native English speakers of diverse backgrounds were recorded and analyzed. The analysis indicated that native speakers did have difficulty modifying their language input; however, native speakers trained to teach English as a Second Language were more successful at language modification. The findings suggest that linguistic input provided by native speakers is not particularly useful for language acquisition, but does have considerable value as a means of improving communicative competence through social and cultural information exchange. Partner exchanges between native and non-native speakers is appended. (JL)