I have written a letter.
結構︰主詞+have(has)+過去分詞+…。
說明︰<現在完成式>用於表示“過去某時”發生的事情，“直到現在”才完成，或“繼續到現在”，或其結果“影響到現在”，它的肯定式由“have(has)+過去<分詞>”構成，其中 have或 has 是<助動詞>，當<主詞>是第三人稱單數(he，she，it…)時，用 has，其餘人稱用 have。
I have written a letter. 我已經寫了一封信。
Mary has studied English for three years. 瑪麗研讀英語已有三年。
He has liked dogs since he was a child. 自從他是小孩時，他就喜歡狗。
... is ...ed by ...
結構︰主詞+be 動詞+過去分詞+by+受詞…。
說明︰將主動句改為被動句時，先將主動句的<主詞>變成被動句的<受詞>，再將主動句的<及物動詞>改成“be+過去分詞”，且須注意 be <動詞>的時式要與主動句的<及物動詞>時式相同，最後將主動句的<主詞>變成被動句 by 的<受詞>。
The news is widely spread by them. 這一消息被他們廣為傳播。
Vegetables are needed every day by us. 蔬菜每天被我們所需要。
This letter was typed by Alice this morning. 這封信在今早被愛麗絲用打字機打過了。

will be V-ed by ...
結構︰主詞+will be+過去分詞+by+受詞…。
說明︰將現在式被動句的 be <動詞>(am，is，are)改為 will be，是構成未來式被動句的一種方法。
That book will be brought by Mary tomorrow. 那本書明天將被瑪麗帶來。
That car will be washed this afternoon. 那部汽車今天下午將會被洗。
The building will be opened next month. 那棟大樓下個月將營業。
be going to be V-ed by
結構︰主詞+be going to+be+過去分詞+by+受詞…。
說明︰在現在式被動句的 be <動詞>(am，is，are)後加 going to be，是構成未來式被動句的另一種方法。
These clothes are going to be washed by her. 這些衣服將由她來洗。
A birthday cake is going to be brought to the table by the cook.
一只生日蛋糕將被廚師放到桌子上。
Music is going to be taught by Miss Lin. 音樂課將由林小姐來教。
can(not) be V-ed by ...
結構︰主詞+can(not)be +過去分詞+by+受詞…。
說明︰將主動句中的<助動詞>(can，must…)照抄，後面加上 be+過去<分詞>，即構成含有<助動詞>的被動句。
That lesson can not be understood by many students. 那一課無法為許多學生所理解。
The question can not be answered by many people. 這一問題無法被許多人回答。
His poor handwriting can not be read by himself. 他糟糕的筆跡無法被他本人所辨認。
... V + V-ing ...
結構︰主詞+動詞+補語(現在分詞)
說明︰英文中，若兩個<動詞>在一起而無<連接詞>加以連接，所表示的動作又是同時發生的，則第二個<動詞>要變成現在<分詞>;若第二個<動詞>是be<動詞>時，應變成現在<分詞> being，但 being通常予以省略。
We sat listening to the sound of the waves. 我們坐著傾聽海浪的聲音。
The dog lay dozing in front of the door. 小狗躺在門前打盹兒。
She stood there (being) motionless. 她站在那兒，一動也不動。
He quickly ran home, looking as if there was something wrong with him.
他快步跑回家，看上去好像有什麼事不對勁。
I stand looking over the lake. 我站著展望湖面。
Some leaves went flying into my room. 幾片葉子飛著進入我的房間。
... V-ing/V-ed + N ...
結構︰…現在分詞/過去分詞+名詞(或名詞+現在分詞/過去分詞)
說明︰這是<分詞>做<名詞>之修飾語的用法，該<分詞>修飾其前或後緊臨之<名詞>;<名詞>之前有其他單字或<片語>跟隨時，<分詞>通常放在<名詞>後面。
The shouting boy did not hear his mother call him. 大聲叫嚷的孩子聽不到媽媽的叫喚。
The girl standing in the front row is my niece. 站在前排的少女是我的姪女。
There were no printed books in those days. 當時沒有印刷的書籍。
This is a play written by an American author. 這是美國作家寫的劇本。
The prisoners closely guarded escaped from the prison last night.
被嚴密監視的這些囚犯昨夜越獄了。
I looked painfully at the vase broken into pieces. 我痛苦地看著這個破得粉碎的花瓶。
It is difficult to shoot a flying bird, especially a small bird flying high up in the sky.
要射中飛行中的小鳥，尤其是高空飛行的小鳥，非常困難。
Soon we came to a crowded street, a very wide street crowded with allsorts of vehicles.
我們很快就來到一條很寬、很吵雜，各種車輛來往行駛的大馬路上。