1.
英語中的簡單句可以分成兩大類：
a）靜態句：主體屬於某一型別，具有某種性質，或者處於某種狀態。句中的動詞通常是系動詞或助動詞。
【例句】I am a student.
b）動態句：主體在進行某一種動作。句中的動詞通常是實義動詞。
【例句】The mother patted the baby.
2.
同一句意思，可以用靜態句表示，也可以用動態句表示。
【例句】 He is a worker in that factory.（靜態句）
【例句】 He works in that factory.（動態句）
3.
英語更喜歡把動態事件當作靜態事件來反映。
【例句】 The camellias were in bloom. 山茶花正在開放。
【例句】 The old life was at an end.
【例句】 I'm in great trouble.
【例句】 She is in a talkative mood today.
【例句】 Was she ever out of temper?
【例句】 I was under the impression that your sister was a doctor.
4.
所有的動態句都可以轉變為靜態句的形式。
【原句】 He described to us his bitter life.
【主語轉為表語】 This is he who described to us his bitter life.
【謂語轉為表語】 That was his description to us of his bitter life.
【直接賓語轉為表語】 Such was his bitter life he described to us.
【間接賓語轉為表語】 It was to us that the he described his bitter life.