(2)if和 whether的选用 不能使用i的情况: a在句首的主语从句 b.表语从句 c.同位语从句 e.介词后的宾语从句 f. whether to do做动词宾语不能用 if to do g. whether or not连在一起引导宾语从句时不用i
(2).if 和whether 的选用 不能使用if 的情况： a.放在句首的主语从句 b. 表语从句 c. 同位语从句 e. 介词后的宾语从句 f. whether to do 做动词宾语不能用if to do. g .whether or not 连在一起引导宾语从句时不用if
(3)疑问词+ever和 no matter+疑问词的区别 ①疑问词+ever可引导名词性从句,在主从句中要充 当一定的部分。如: Whoever breaks the rule must be punished You can choose whatever you like in the shop ②疑问词+eVer还可引导让步状语从句。如: Whoever breaks the rule, he must be punished Whatever you do, you must do it well ③ no matter+疑问词只能引导让步状语从句。如: No matter what you do, you must do it well No matter who breaks the rule, he must be punished
（3）疑问词 + ever和no matter + 疑问词的区别 ①疑问词 + ever可引导名词性从句，在主从句中要充 当一定的部分。如： Whoever breaks the rule must be punished. You can choose whatever you like in the shop. ②疑问词 + ever还可引导让步状语从句。如： Whoever breaks the rule, he must be punished, Whatever you do, you must do it well. ③no matter + 疑问词只能引导让步状语从句。如： No matter what you do, you must do it well. No matter who breaks the rule, he must be punished
(4)其它连接代词和副词的选用 主要根据名词性从句中的具体意义,正确的选择who、 which、when、 where、why、how等连接词,这些连 接词既具有疑问含义,又起连接作用,同时在从句中 充当各种成分。 我们何时举行运动会还没有决定。 When we shall hold our sports meeting is not decided. 这就是我忘记眼镜的地方。 This is where I left my glasses
（4）其它连接代词和副词的选用 主要根据名词性从句中的具体意义,正确的选择who、 which、when、where、why、how 等连接词，这些连 接词既具有疑问含义，又起连接作用，同时在从句中 充当各种成分。 我们何时举行运动会还没有决定。 ________ we shall hold our sports meeting is not decided. 这就是我忘记眼镜的地方。 This is _________ I left my glasses. When where
名词性从句中的时态呼应 (1)宾语从句中主句和从句的时态保持一致 a.如果主句时态是现在时或将来时,从句谓语 可根据句意需要而选用任一种时态 He believes his dream will come true some day Please tell mewhat you were doing at this time yesterday b.如果主句谓语是过去时,从句谓语动词一般用过去的 某种时态,但从句表达的是客观事实、真理、自然规 律等时,从句谓语通常用一般现在时。 He told me he was preparing for the examination He told me He had been away from his hometown for ten years The teacher told us light travels in a straight line
名词性从句中的时态呼应 （1）宾语从句中主句和从句的时态保持一致. a. 如果主句时态是现在时或将来时,从句谓语 可根据句意需要而选用任一种时态. He believes _________________________ . Please tell me _________________________. his dream will come true some day what you were doing at this time yesterday b. 如果主句谓语是过去时,从句谓语动词一般用过去的 某种时态,但从句表达的是客观事实、真理、自然规 律等时，从句谓语通常用一般现在时。 He told me ______________________ . He told me ______________________. The teacher told us ______________________ he was preparing for the examination He had been away from his hometown for ten years light travels in a straight line