Additional information Voiceless fricative /0/as in "thin and voiced fricative/o/as 8 4. 65 in "the do not occur in Chinese. Learners tend to substitute voiceless/t/or /s/for voiceless θ/，so that“thin”sounds like“tin or“sin”,and“them”sounds like “dem”or“zem”. Additional information ◼ Voiceless fricative / θ / as in “thin and voiced fricative / ð/ as in “the do not occur in Chinese. Learners tend to substitute voiceless /t/ or /s/ for voiceless / θ /, so that “thin” sounds like “tin” or “sin”, and “them” sounds like “dem” or “zem