郭岱宗（英文系副教授）

“Must”是兩面人

“Must”有兩個意思，一個是「必須」，一個是「一定」，它們的過去式經常被錯用。其實，只要學習得法，兩者一點也不難區分。

1.must(必須)=have to

過去式：

I had to go.

2.must(一定)本身並沒有過去式，它的過去式只要在must後面「借」用現在完成式即可。

※記憶口訣：「一定」要「借」

現在式：

You must be angry. 你一定生氣了。

過去式：

You must have been angry yesterday. 你昨天一定是生氣了。

現在完成式

題目：

1.我一定是醉了。

I drunk.

2.我昨晚一定是醉了。

I drunk last night.

3.他必須去。

He go.

4.他昨天必須去。

She go yesterday.

5.她一定是生病了。

She sick.

6.她昨天一定是生病了。

She sick yesterday.

7.我昨天必須問他那個問題。

I ask him that question yesterday.

8.你再不走，我就必須叫警衛了。

I call the security if you don’t leave.

9.他一定己經那麼做了！

He it！

10.誰說你必須離開的。

Who said you go.

11.我當時一定是糊塗了！(糊塗：lose my mind)

I .

12.你一定弄錯了。

You wrong.

13.你當時一定弄錯了。

You wrong.

14.她必須嫁給他。

She him.

15.她一定已經嫁給他。

She him.

答案：

1.must be (現在式)

2.must have been (過去式)

3.has to (現在式)

4.had to (過去式)

5.must be (現在式)

6.must have been (過去式)

7.had to (過去式)

8.will have to (未來式)

9.must have already done (過去式)

10.had to (過去式)

11.must have lost my mind (過去式)

12.must be (現在式)

13.must have been (過去式)

14.must marry (現在式)

15.must have married (過去式)