People from all walks of life, aged 20 to 83, attend these classes.

= People from all walks of life, who are aged 20 to 83, attend these classes.

上課的人來自各行各業, 年齡從二十歲到八十三歲都有。

表示年齡的用法如下:

　人 + be aged + 數字　　某人幾歲

= 人 + be + 數字 + year (s) + old

例: My grandfather is aged ninety-seven.

     = My grandfather is ninety-seven years old.

    (我爺爺已經九十七歲了。)

＊ 在"人 + be  + 數字 + year (s) + old"中, year (s) old可一併 省略。

     My grandfather is ninety-seven years old.

→ My grandfather is ninety-seven years.  (╳)

→ My grandfather is ninety-seven. (○)

＊上述用法中的old亦可用of age取代。

     My grandfather is ninety-seven years old.

     = My grandfather is ninety-seven years of age.

As you enter the class, you must shout out, "Konbanwa!" (Good evening!) as loudly and cheerfully as possible.

你踏進教室時, 必須盡可能大聲而愉快地喊"Konbanwa!" (日語的『晚上好！』)。

表示『盡可能地……』的用法如下:

   as + 形容詞/副詞 + as possible　　盡可能地……

= as + 形容詞/副詞 + as one can

注意:

在上述用法中, 第一個as為副詞, 表『一樣地』, 故其後須接形容詞或副詞以供修飾; 而第二個as則為副詞連接詞, 表『和』, 引導副詞子句, 修飾第一個as, 故"as...as"譯成『和……一樣地』。

理論基礎:

a. as possible係為as it is/was possible化簡而成, it是代名詞, 代替其前述詞部分的概念, 實際使用時, it is/was一定要省略, 已成固定用法。

例: He remained as quiet as possible.

     (他盡可能地保持安靜。)

＊ 本句原為"He remained as quiet as it was possible.", it即代替remaining quiet (動名詞片語, 作主詞) 的概念。

     You must study as hard as possible.

     (你要盡可能地用功。)

＊ 本句原為"You must study as hard as it is possible.", it即代替studying hard (動名詞片語, 作主詞) 的概念。

b. as one can之後即省略了與其前主要子句中相同的述詞部分, 以避免重覆。

例: He remained as quiet as he could.

   → He remained as quiet as he could (remain quiet) .

     = He remained as quiet as possible.

＊ 本句as he could之後即省略了與其前相同的述詞部分remain quiet。

     You must study as hard as you can.

→ You must study as hard as you can (study hard) .

     = You must study as hard as possible.

＊本句as you can之後即省略了與其前相同的述詞部分study hard。

Then you're supposed to make direct eye contact and smile as you shake hands with your classmates.

接著, 你和同學握手時, 應該面帶微笑地注視著對方。

本句中, 使用了"be supposed to  + 原形動詞"的句型, 此乃表『應當』之委婉說法。

表示『應當』、『應該』、『必須』時, 其語氣強弱的用法如下:

a. 用must (必須)、have to (必須, 不得不) 的語氣最強。

例: You must finish your work before you leave.

     (你必須做完工作才能離開。)

     You have to finish your work before you leave.

     (你得做完工作才能離開。)

b. should的語氣稍弱。

例: You should finish your work before you leave.

(你應該做完工作才能離開。)

c. 使用"be supposed to + 原形動詞"時, 則語氣最弱, 為較委婉的說法。

例: You are supposed to finish your work before you leave.

　(你應當做完工作才能離開。)