下面小编跟大家一起了解英语四级语法之虚拟语气/错综时间条件句,希望对大家的学习有所帮助。
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.