专题八情态动词、系动词和助动词 一、情态动词【温馨提示】(1)mustnt 表示否定意义, 意为“禁止; 不允许”。Drivers mustnt drive after drinking. 决不允许司机酒后驾车。(2)have to 有人称、数和时态的变化, 强调受客观条件的限制, 意为“不得不”。Grandma is ill. I have to look after her. 奶奶病了, 我得照顾她。(3)May. . . ? 句式的否定回答: No, . . . cant. (4)Must. . . ? 句式的否定回答: No, . . . neednt/. . . dont/doesnt have to. Must I clean room now? No, you neednt. /No, you dont have to. 我现在必须打扫房间吗? 不, 你不必。【即学活用】1. Mike replied, with a big smile, “Oh, you _to worry about them. ”A. not to need B. needntC. not need
