Hello小马哥, 有个困扰了我很久的英文发音问题想请教一下:有很多以s结尾的单词其尾音为/z/,比如is, has, because等等,虽然大多数时候大家的发音都是准确的z,但我发现native speaker也经常会将/z/的音发成/s/,所以ending s音在英语中到底是如何念的呢? Original Question: when to pronounce the ending voiced s(/z/) like a short, weak, unvoiced s(/s/)? I've collected a bunch of video and audio materials regarding that, I found that for most of time, people say "iz""becauze""az", while sometimes (like 10 to 20 percents), people say "is""because""as", and now I'm quite confused about how the ending z is really pronounced.