1.與所指代的名詞在性、數、格上是否一致

　　如：Each cigarette a person smokes does some harm, and eventually he may get a serious disease from its effect.

　　It was during the 1920’s that the friendship between the two American writers Hemingway and Fitzgerald reached its highest point.

　　Our department was monitored by two supervisors, Bill and me.

　　2.that的指代作用

　　that指代不可數名詞和單數可數名詞(如是復數，用those)，后面通常跟有修飾語，如出現在比較結構中的that of。如：

　　Conversation calls for a willingness to alternate the role of speaker with that of listener, and it calls for occasional “digestive pauses” by both.

　　No bread eaten by man is so sweet as that earned by his own labor.

　　3.one的指代作用

　　one指代帶不定冠詞的單數可數名詞，復數為ones。the one 指代帶定冠詞的單數可數名詞。如：

　　A good writer is one who can express the commonplace in an uncommon way.

　　4.do的替代作用

　　do代替動詞，注意數和時態的變化。如：

　　For him to be re’elected, what is essential is not that his policy works, but that the public believe that it does.