正文
举个例子，在口语中我们可能会说：She was kind of strange, but I liked her. 其中 kind of 就是典型的口语用词，这句话如果要用书面语表达出来，可以改成：She was somewhat strange, but I liked her.
又比如，在口语中可以说：He quitted his job and planned to go travelling around the world. 其中 quit his job 以及 go travelling the world 属于非正式表达，在正式写作中可以改成 He left his job and planned to travel around the world. 或者是 He resigned and planned to travel around the world.
此外，书面语中关联词的使用也与口语有所不同，比如口语中经常使用 and 以及 so，而书面语中则会使用 therefore, thus, hence, as a result, accordingly, consequently 等。
英国作家 A.G. Gardiner 曾经写过一篇很有趣的文章 On Big Words，从文章里面我们可以看到口语和书面语的词汇区别：
I was cutting down the nettles by the hedge with a billhook when a small man with spectacles, a straw hat, a white alpaca jacket, and a book under his arm came up, stopped, and looked on. I said "Good evening," and he said "Good evening." Then, pointing to my handiwork, he remarked:
"You find the nettles very difficult to
eradicate
?"
I said I found them hard to keep down.
"They
disseminate
themselves most
luxuriantly
," he said.
I replied that they spread like the dickens.
"But they
have their utility
in the
economy of Nature
," he said.
I replied that Nature was welcome to them as far as I was concerned.
He then remarked that it was most
salubrious weather
, and I agreed that it had been a fine day. But he was afraid, he said, that the
aridity
of the season was
deleterious
to the crops, and I replied that my potatoes were doing badly. After that, I think, it occurred to him that we did not speak the same language, and with another "Good evening" he passed on and I returned to the attack on the nettles.
上面这段对话中两个人语言风格迥异，文中的“我”用词自然，是典型的日常生活口语。而手夹书本，头戴帽子的那个人说话则装腔作势，刻意在对话里面使用 eradicate, disseminate, luxuriantly 这些只有在书面语中才会出现的大词，效果适得其反。
