定語從句缺主語代替人who/that 代替物which/that

定語從句缺賓語代替人whom/that代替物which/that

定語從句缺補語代替人that 代替物that

定語從句不缺成分,先行詞表示地點用where

原因用why

時間用when

方式用the way that

賓語從句：引導陳述句用that

引導一般疑問句用if

引導選擇疑問句用whether...or

引導特殊疑問句做主語用who what

做賓語用whom what

做補語用who what

做定語用whose what which

做狀語用where when why how

引導感嘆句用原感嘆詞或變成that從句

引導祈使句用to do 或變成that從句

賓語從句定語從句引導詞的區別

what who when why where whose引導賓語從句時有疑問意義,引導定語從句時無疑問意義.