1. than 引導的副詞子句句構必須與主要子句句構一致:
a. 主要子句的結構為 "主詞 + be 動詞" 時,than 引導的副詞子句結構亦應為 "主詞 + be 動詞"。
例: Peter is more handsome than David is.
(彼得要比大衛更瀟灑。)
b. 主要子句的結構為 "主詞 + 助動詞(如 can、will、may 等)",than 引導的副詞子句結構亦應為 "主詞 + 助動詞"。
例: Jane can sing such better than Vicky can.
(珍歌唱得要比薇琪棒。)
c. 主要子句的結構為 "主詞 + 動詞" 時,than 引導的副詞子句動詞則以助動詞 do、does 或 did 取代。
例: This car runs faster than that one runs.(劣,動詞 runs 重複)
→ This car runs faster than that one does. (○)
(這輛車要比那一輛跑得快。)
2. than 引導的副詞子句中 be 動詞、助動詞或 do、does、did 可予省略,僅保留主詞。故上列各例句亦可改寫如下:
Peter is more handsome than David (is).
Jane can sing much better than Vickey (can).
This car runs faster than that one (does).
3. than 引導的副詞子句句構亦可採問句式倒裝句構:
a. be 動詞
Peter is more handsome than is David.
b. 助動詞
Jane can sing much better than can Vickey.
c. 動詞 do、does、did
This car runs faster than does that one.
The general manager fired two employees for stealing.
總經理將 2 位偷竊的員工開除了。