4. 在做宾语从句的题目时应注意两点
(1)时态：
①当主句是现在时态时，宾语从句可以根据需要使用任何时态。
I dont know when he will come back.我不知道他将何时回来。
He tells me that his sister came back yesterday.他告诉我他姐姐昨天回来了。
②当主句是过去时态时，宾语从句必须是一种过去的时态。
She asked me if I knew whose pen it was.她问我是否知道这是谁的钢笔。
He said that he could finish his work before supper.他说他会在晚饭前完成工作。
③当表示客观事实或普遍真理的句子做宾语从句时，任何时候都用一般现在时。
The teacher said that the earth goes round the sun.老师说过地球绕着太阳转。
(2)语序：
任何从句都使用陈述句语序，宾语从句当然也不例外。
同学们只要掌握了以上内容，应对宾语从句的题目就不成问题了。
二. 介词by的用法
1. 意为在旁，靠近。
Some are singing and dancing under a big tree. Some are drawing by the lake.
有的在大树下唱歌跳舞。有的在湖边画画儿。
2. 意为不迟于，到时为止。
Your son will be all right by supper time.
你的儿子在晚饭前会好的。
How many English songs had you learned by the end of last term?
到上个学期末你们已经学了多少首英语歌曲?
3. 表示方法、手段,可译作靠、用、凭借、通过、乘坐等。
The monkey was hanging from the tree by his tail and laughing.
猴子用尾巴吊在树上哈哈大笑。
The boys father was so thankful that he taught Edison how to send messages by railway telegraph.
孩子的父亲是那么的感激,于是他教爱迪生怎样通过铁路电报来传达信息。
4. 表示逐个，逐批的意思。
One by one they went past the table in the dark.
他们一个一个得在黑暗中经过这张桌子。