常见的有: bad , brave , careless, clever , cruel , foolish , 3 good(好心的), honest , horrible , kind , lazy , modest , naughty , nice(有教养的), polite, rude , silly , stupid , wise , wrong(错误的)等。 这个句型可以改写为:sb. is kind to do sth. It is kind of you to say so. = You are kind to say so. 18. It is necessary ( for sb. ) to do sth. 该句型与上一个同属一个句型。如果不定式的逻辑主语是由 for 引起,主句中的形容词通常 是表示重要性,紧迫性,频繁程度,难易,安全等情况的形容词。常见的形容词有:① important, necessary, natural ② easy , safe , common , normal , hard , difficult , dangerous , unusual, rare , impossible , pleasant 等。 在①中的形容词作表语可以用从句改写, 如: It is important for her to come to the party. = It is important that she (should ) come to the party 19. It looks ( seems ) as if ... 该句型中 it 无意义。 as if 引导一个状语从句。常译为,"看起来好象..."如果与事实 不相符合,则用虚拟语气. It looks as if he is ill.(真的病了) It looks as if he were ill. (没有生病) It seemed as if he were dying. 20. We think it important to learn a foreign language. 该句型中的 it 作形式宾语。为了记忆方便我们可称该句型为"6123 结构"。 6 指主句中常用的动词:think, believe, make, find, consider, fee