22.一般现在时的特殊用法
<例句>
I am busy all day tomorrow.
我明天整天都忙。
<语法分析>
当be表示根据时间或事先安排肯定会出现的状态时，一般现在时可代替将来时态，在以下情况如在时间状语或条件状语从句中，在主句的谓语动词是将来时的定语从句和宾语从句中，在表示比较结构中的比较状语从句中，一般现在时可代替将来时态。在here和there引导的句中，常用一般现在时代替现在进行时态。
<触类旁通>
(1) Tell him about that when he comes.
他来时把那件事请告诉他。
语法分析：在时间状语从句中，一般现在时可代替将来时态。
(2) I'll stay with you so long as there is a room free.
只要有空房，我就和你住一起。
语法分析：在条件状语从句中，一般现在时可代替将来时态。
(3) Look, here comes your sister.
看，你姐姐来了。
语法分析：在here引导的句子中，常用一般现在时代替现在进行时态。
(4) There goes the bell.
打铃了。
语法分析：在there引导的句中，常用一般现在时代替现在进行时态。
(5) The first person who opens that door will get a shock.
第一个开门的人会大吃一惊的。
语法分析：在主句的谓语动词是将来时的定语从句和宾语从中，will不可省略。
<巩固练习>
(1) Her daughter won't go to bed until she ____[finish] her lesson.
(2) I'll write to your mother if you _____[be] not here on time tomorrow.
(3) They'll have an outing at the seaside if the weather _____[permit].
(4) If she won't arrive before eight, there _____[be] no point in ordering dinner for her.
(5) If they are burned, they ____[give] off poisinous gases.
(6) When _____ our school begin?
(7) My brother's birthday _____ in three weeks' time.
(8) It _____ Sunday tomorrow, you know.
(9) There _____[go] the last bus.
<参考答案>
(1) finishes (2) are (3) permits (4) is (5) give (6) does (7) is (8) is (9) goes