如何使用英文情態動詞？它們是什麼？

如果不學習的話，英文情態動詞會令人困惑且棘手。身為語言學生，了解大量英文情態動詞才能熟悉它們，也有助於在交談時輕鬆表達自己的想法。 

英文情態動詞是用來表達可能性或機率、能力、許可和請求、必要性或義務的動詞。它們是助動詞能幫助表達完整句子。

英文常見的 8 個情態動詞是 may、might、can、could、should、will、would 和 Must。

英文情態動詞用於以下情況。

1. 可能性或機率 – 如果我們相信某件事在某個時刻是可能的、不可能的或確定的，我們就會使用英文情態動詞。

• 可能或不可能 – 我們用may、might 和could 來表示我們認為將來可能發生但我們不確定的事情。

Mary might be seeing Tom in LA in the summer.
There may be a conference at the end of this quarter.
If given much attention, the spread of the virus could be prevented.

對於否定性陳述，我們可以在句子中加上「no」。

            Mary might not be seeing Tom in LA in the summer as she has more important meetings.
            There may not be a conference at the end of this quarter because of the pandemic.

• 肯定 – 如果我們確定某件事，我們會使用情態動詞「must do」和「can’t do」。

You must be so stressed out; you look so exhausted.
She must be inside the office. Her office door is open.
Being a single mom can’t be easy knowing that she doesn’t have somebody to rely on.           

在某些情況下，情態動詞「should/shouldn’t」會用來表達我們對未來的期望。

Take your medicine and sleep. You should be well in a day.
The decrease in sales shouldn’t be my problem.

2. 能力 –這種用法最常用的情態是“can/could”，因為它表示做某事的能力的想法。

Ms. Brooks can dance gracefully without music.
I could easily get a perfect score on my exams when I was in elementary.

            對於否定形式，我們在句子中加上“not”。

She cannot process her documents alone.
The police could not arrest the suspect because he was disguised. 

3. 許可和請求 – 我們使用情態動詞 may、can 和 could 來請求許可或提出請求。

May I go to the restroom? – a formal way of asking permission
Can my son take a leave on Monday? – a casual way of asking permission
Can you please share the file with me? – a casual but polite way of making a request
Could you open the door for me, please? – a polite way of making a request
Will you shut up and do your job?
Would you allow me to carry these books for you, ma’am?

4. 必要性或義務 – 我們使用英文情態動詞來表示某些必須要做的事情。

You must finish your report before the end of your shift.
The project manager should find ways to fix the issue.