Tā fàn guò de cuòwù bùyī'érzú, hěn nán yīyī lièjǔ.
The mistakes he has made are too many and varied to list one by one.
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From 《公羊传·文公九年》: '始有大夫，则何以不氏？许夷狄者，不一而足也。' The Gongyang Commentary uses 不一而足 to explain that the classification of certain groups is not based on a single criterion.
usage
Almost always sentence-final, following a list or the topic it describes. Typical template: '...的例子 / 情况 / 问题 + 不一而足'. Formal register — more literary than 多得很 or 很多.
