A study investigated to what extent adult native speakers of Mandarin Chinese learning English as a second language could pronounce the five front vowels of American English, how difficult this was, and which vowels were most difficult. Subjects were 16 Chinese university students and spouses and 16 American students. All subjects were recorded producing five words ("beat, bit, bait, bet, bat") in the sentence "I say------now." Production was digitized and the frequencies analyzed using a sound spectrograph. Results are presented separately for male and female subjects. They indicate that Chinese speakers were successful in producing native- or near-native-like frequencies for several phonemes and a diphthong. In the case of two phonemes, there was little difference between Chinese and native productions. Some conclusions were: among the five American English front vowels, /ey/ and /ae/ are the easiest ones for adult Mandarin Chinese speakers to pronounce; and /iy/ lies in the middle of the scale of difficulty. Contains 59 references. (MSE)