Two forms are a minimal pair when they meet three conditions :1)they are different in meaning ,2) they differ only in one sound segment ,3)the different sounds occur in the same position in the strings .When a group of words meet all the three conditions ,they are called a minimal set.　当两种形式符合以下三种条件时，他们就是最小对立体或者最小对立对，第一，他们的意思不一样，第二，他们只有一个语音切分不一样，第三，不同的语音在同一个位置。当一组单词满足这三个条件，他们就是最小对立集。