情况的假设,而主句可能是对现在正在进行情况的假设。这种句子称为错综时间条件 句 If the weather had been more favourable the crops would be growing still better 7.某些主语从句中的谓语动词要用虚拟语气 某些表示命令,要求,决定,建议,主张以及“重要性”和“紧迫性”等概念的主语从 句中谓语动词要用虚拟语气。这时,谓语动词用动词原形或 should+动词原形。这类主 语从句一般由“Itis(was)+形容词/过去分词+th引导的从句”构成。该结构中, 常用的形容词主要有: advisable, appropriate, desirable, essential, Imperative, Important necessary, obligatory., prope;, urgent, vital等;常用的过去分词主要有: arranged, decided, demanded, desired, ordered, proposed, recommended, requested, suggested F It is necessary that you( should) stop smoking so heavily It is arranged that you(should) enter for this competition 8.asif/ though引起的从句 当asif/ though引起的从句所表达的内容完全与实际情况相反或者纯粹是一种假设时, 通常要用虚拟语气。如果从句表示与现在的事实相反,谓语动词用一般过去时:如果从 句表示与过去的事实相反,谓语动词用过去完成时:如果从句表示与将来的事实相反, 谓语动词用 would( might, could)+动词原形; They talked as if they had been friends for years I remember the whole thing as if it happened yesterday It looks as if it might rain Note:如果asif/ though引起的从句所表达的内容被看作是事实或者有可能是真实的, 则要用陈述语气 It seems as if it is going to rain. The meat tastes as if it has already gone bad 9.lest, for fear tha和 In case引起的从句 当lest, for fear that和 In case表示“以免,以防,生怕,惟恐”等时,在它们引起的从 句中,谓语动词常用 should+动词原形。 He ran away lest he should be seen. He's working hard for fear that he should fall behind He left early in case he should miss the last train 10. I f only引出的从句 Ifon引出的从句用以表达感叹性的愿望,常译为“要是…就好了"。 If only从句经常 省略结果主句,且主要用在虚拟语气中,即从句的谓语动词用一般过去时表示现在或将 来不可能实现的愿望,或用过去完成时表示过去没有实现的愿望。 If only the rain would stop If only I'd listened to my parents. Note: if only引出的句子偶尔也可使用陈述语气,但考生须注意的是,在各类测试中 般都以用虚拟语气为正确答案。 11. wou ld rather(that)引出的从句情况的假设，而主句可能是对现在正在进行情况的假设。 这种句子称为错综时间条件 句. If the weather had been more favourable, the crops would be growing still better. 7. 某些主语从句中的谓语动词要用虚拟语气 某些表示命令，要求，决定，建议，主张以及“重要性”和“紧迫性”等概念的主语从 句中谓语动词要用虚拟语气。这时，谓语动词用动词原形或 should +动词原形。这类主 语从句一般由 “It is (was) + 形容词／过去分词 + that 引导的从句”构成。该结构中， 常用的形容词主要有：advisable, appropriate, desirable, essential, imperative, important, necessary, obligatory, proper, urgent, vital 等；常用的过去分词主要有：arranged, decided, demanded, desired, ordered, proposed, recommended, requested, suggested 等。 It is necessary that you (should) stop smoking so heavily. It is arranged that you (should) enter for this competition. 8. as if / though 引起的从句 当 as if / though 引起的从句所表达的内容完全与实际情况相反或者纯粹是一种假设时， 通常要用虚拟语气。如果从句表示与现在的事实相反，谓语动词用一般过去时；如果从 句表示与过去的事实相反，谓语动词用过去完成时；如果从句表示与将来的事实相反， 谓语动词用 would (might, could) + 动词原形； They talked as if they had been friends for years. I remember the whole thing as if it happened yesterday. It looks as if it might rain. Note: 如果 as if / though 引起的从句所表达的内容被看作是事实或者有可能是真实的， 则要用陈述语气。 It seems as if it is going to rain. The meat tastes as if it has already gone bad. 9. lest, for fear that 和 in case 引起的从句 当 lest, for fear that 和 in case 表示“以免，以防，生怕，惟恐”等时，在它们引起的从 句中，谓语动词常用 should + 动词原形。 He ran away lest he should be seen. He’s working hard for fear that he should fall behind. He left early in case he should miss the last train. 10. If only 引出的从句 If only 引出的从句用以表达感叹性的愿望，常译为“要是…就好了”。If only 从句经常 省略结果主句，且主要用在虚拟语气中，即从句的谓语动词用一般过去时表示现在或将 来不可能实现的愿望，或用过去完成时表示过去没有实现的愿望。 If only the rain would stop. If only I’d listened to my parents. Note: if only 引出的句子偶尔也可使用陈述语气，但考生须注意的是，在各类测试中一 般都以用虚拟语气为正确答案。 11. would rather（that）引出的从句