判斷從句性質(zhì)方法：
1．依據(jù)從句在句中的位置特點(diǎn)（尤其適用于名詞性從句及定語從句）；
e.g. he said（v. 說） that he would come（來）.
e.g. did you see the letter（n. 信） that i sent（寄） him?
2． 依據(jù)連接從句的連詞使用特點(diǎn)（e.g. because, although， though, before, after, until/till, lest, in order that， unless， as(so) long as， in case， however）
e.g. i do it because i like（喜歡） it. 我做這件事是因?yàn)槲蚁矚g。
3． 依據(jù)從句的句子結(jié)構(gòu)特點(diǎn)（如引導(dǎo)從句的連詞是否在從句中充當(dāng)某個(gè)語法成分）
e.g. he said（v. 說） that he would come.
e.g. did you see the letter（n. 信） that i sent him?
e.g. he can run as fast（很快地） as i can.（as...as.../與...一樣地...）
4. 從句與主句在意義上的相互關(guān)系；
e.g. i met（預(yù)見） her while（在...期間） i was at school（在學(xué)校）.
e.g. you like tennis（網(wǎng)球）, while i'd rather(寧愿) read.