1、一、引导词
1．从句为陈述句，常选择引导词that，that引导宾语从句无意义，不充当句子成分常省略。例句：He told us （that）they would help us through the whole work.
2．从句为一般疑问句，常选择引导词if或whether，表示“是否”。在 whether … or not 结构中不能用 if 替换。例句：I don't know if there will be a bus any more.
3. 从句为特殊疑问句，常选择what，when，where，which，who，how等的疑问代词、副词作引导词。例句：He didn't tell me when we should meet again.
2、二、判断时态情况：
1.主句是一般现在时，从句可以为各种时态。
2.主句是一般过去时，从句要用相应过去时态。
注意：从句描绘客观事实、真理、自然现象等，从句时态不受主句时态限制，仍用一般现在时。
例句：He answered that he was listening to me.
Father told me that practice makes perfect .
3、三、宾语从句的语序要用陈述句语序
陈述句语序，就是主语在前，谓语动词在后。
错误：He is wondering when can he finish this difficult job.
正确：He is wondering when he can finish this difficult job.
