1.Because he was ill yesterday, so he didn't go to work. (×)
Because he was ill yesterday, he didn't go to work. (√)
He was ill yesterday, so he didn't go to work. (√)
[析] 用though, but表示"虽然……，但是…… "或用because, so 表示"因为……，所以……"时，though和but 及because和so 都只能择一而用，不能两者同时使用。
2.The Smiths have moved Beijing. (×)
The Smiths have moved to Beijing. (√)
[析] 不及物动词后接名词或代词作宾语时，要在动词之后加上适当的介词；但不及物动词后接home, here, there等副词作宾语时，动词之后不必加任何介词。
3.The box is too heavy for him to carry it. (×)
The box is too heavy for him to carry. (√)
[析] the box既是这句话的主语, 也是不定式to carry的逻辑宾语，若句末再加上it，就和the box重复了。
4.Each of the boys have a pen. (×)
Each of the boys has a pen. (√)
[析] 复数名词前有表个体的each of, one of, every，either of等词组修饰，或有表否定的neither of, none of 等词组修饰时，谓语动词要用单数形式。
5.例:那是你心软！我不就是一个例子吗？
Neither he nor you is good at English. (×)
Neither he nor you are good at English. (√)
[析] either... or..., neither... nor..., not only..., but also... 等词组连接句子的两个主语时，谓语动词遵循"就近一致原则", 即由靠近谓语的那个主语决定谓语的人称和数用何种形式。
6.Ten minus three are seven. (×)
Ten minus three is seven. (√)
[析] 用英语表示加（plus）、减(minus)等数学运算时，谓语动词也用单数形式。
7.The number of the workers in this factory are about 5,000. (×)
The number of the workers in this factory is about 5,000. (√)
[析] the number of表示"……的数量"，谓语动词用单数形式；a number of 的意思是"若干"或"许多"，相当于some或a lot of，和复数名词连用，谓语动词用复数形式。
8. 例. Hello! I have important something to tell you. （×）
Hello! I have something important to tell you. (√)
[析] 形容词或动词不定式修饰不定代词作定语时，修饰成分要置于不定代词之后。
9. His son is enough old to go to school. （×）
His son is old enough to go to school. (√)
[析] enough作形容词修饰名词时，可以放在名词前，也可放在名词后；作副词修饰形容词或副词时，只能放在形容词或副词之后。
10.. Here is your sweater, put away it.（×）
Here is your sweater, put it away. (√)
[析] put away, pick up, put on等"动词+副词"构成的词组后接代词作宾语时，代词只能放在动词和副词之间。