【正确答案】：
WHEN IDIOMS ARE USED IN ACTUAL CONTEXT, THEY DO EXPERIENCE GRAMMATICAL CHANGES SUCH AS DIFFERENT FORMS OF VERBS, AGREEMENT OF PERSONAL PRONOUNS AND NUMBERS AND SO ON. THE VARIATIONS IN CONSTITUENTS OF IDIOMS MAY BE REALIZED BY ADDITION, DELETION, REPLACEMENT, POSITION-SHIFTING, DISMEMBERING, ETC.
【题目解析】：当习语在实际语境中使用时，它们确实经历了语法上的变化，如动词的不同形式、人称代词和数字的一致性等。习语成分的变化可以通过添加、删除、替换、移位、分解等方式来实现。