英语句型转换之一肯定句变否定句的技巧请同学们记住以下单词：1、be动词的五种形式：am, is, are, was, were；2、情态动词：can, could, may, might, must, shall, should, will,would, need, had better3、助动词：have, has, had一、动词后直接加not原句中含有be动词(am, is, are, was, were) 和情态动词(can, shall, will, may, should, would, might, had better等)时，要在动词后直接加not。如：1. I am a teacher. I am not a teacher. 2. Li Lei can swim. Li Lei cannot（ cant ）swim. 3. He will go to the zoo if it rains tomorrow. He will not（wont）go to the zoo if it rains
