The addition and deletion of words are mostly function words. Words that need to be added or deleted include articles, prepositions, conjunctions, auxiliary verbs and indefinite symbols. , but generally do not add or subtract verbs, nouns, adjectives and other words with practical significance. Otherwise, the original meaning of the sentence will change.

Content words, such as verbs, nouns, adjectives, adverbs, etc. , change the form, rarely replaced by other words, can not be arbitrarily added or deleted, so as not to change the meaning of the article. The original meaning of this sentence must be changed. To change the problem, we must copy the original meaning of the sentence. In other words, the meaning expressed in the article cannot be changed. Including the logical relationship between mood and context, can only correct the mistakes in language, grammar and logic in the essay.