1.不省略的英语一般比省略的英语更正式。以下是一些例子(括号中的词在非正式英语中可以省略)：
Buy stock in the combined company, if you want to (buy).
如果你想买这家新合并公司的股票，就买吧。
He is the charming guy (whom) I met in the annual meeting the other day.
他就是那天我在公司年会上碰到的那位迷人先生。
I spent weeks (in) doing the market survey.
我花了几周时间做市场调研。
2.倒装句比非倒装句更正式。以下是一些例子(括号中的句子为非倒装句)：
Under no circumstances should he break the rules. (He should break the rules under no circumstances.)
无论在任何情况下，他都不应该犯规。
Barely did I understand the contract. (I barely understood the contract.)
我没怎么看懂合同。
Had I known it I would have told you. (If I had known it I would have told you.)
如果我事前知道这事儿的'话，我会告诉你的。
3.主谓一致比主谓不一致更正式。以下是一些例子(括号中的词为主谓不一致的情况)：
None of them has (have) made progress in the negotiation.
他们都没有在谈判中取得进展。
If I were (was) you I would choose to postpone the project.
如果我是你，我会选择将项目延期。
4介词前提比介词结尾的句子更正式。以下是一些例子(括号中的用法为非正式的用法)：
This is the river along which we used to walk. (This is the river which we used to walk along.)这就是我们从前常常散步经过的河流。
5请求别人做某事时，一些情态动词比另一些正式。以下是一些例子(括号中的情态动词为非正式情态动词)：
May (Can) I start to introduce our products now?
我可以现在开始介绍我们的产品吗？
Would/Could (Will/Can) you get me a copy of the price list?
你能帮我弄一份报价单的复本吗？
6.从句比不定式正式。以下是一些例子(括号中的为不定式形式)：
It is important that we should establish business relations right away. (It is important for us to establish business relations right away.)
重要的是我们应该马上建立商务关系。
It seems that he’ll be late for the meeting. (He seems to be late for the meeting.)
看来他开会要迟到了。
