1. Could I borrow a pen and three pieces of paper?

能借我一支筆和3張紙嗎？

還能這樣說：

Can you give me a pen and three pieces of paper?

Would you lend me a pen and three pieces of paper?

應用解析：

a piece of cake 輕松愉快的事情；

break into pieces 使成為碎片；

by the piece 按件計算

come to piece 破碎，碎裂；身體（精神）垮下來；崩潰

2. I want to write a letter to my pen friend.

我想給我的筆友寫封信。

還能這樣說：

I want to write to my pen friend.

I would like to write a letter to my pen friend.

諺語：

Never write what you dare not sign.

不要寫你不敢署名的文章。

3. My dear mother. I am missing you very much.

親愛的媽媽，我非常想念你。

還能這樣說：

Dear mom, I miss you so much.

To my great mom, I miss you terribly.

諺語：

Poverty is the mother of all arts.

窮后而工乃是藝術之道。

4. She writes to her friend once a week.

她一星期給她的朋友寫一封信。

還能這樣說：

Every week, she writes to her friend.

She writes a letter to her friend once a week.

應用解析：

all at once 突然；同時；

at once 立刻，馬上；同時；

every once in a while 偶爾；

once too often 又一次