While there are certainly many more varieties of English, American English and British English are the two varieties that are taught in most ESL/EFL programs. Generally, it is agreed that no one version is "correct," but there are certainly preferences in use. The three major differences between American and British English are:
当然还有更多的英语种类，但美式英语和英式英语是在大多数ESL/EFL课程中教授的两个种类。一般来说，大家都认为没有一个版本是“绝对正确的”，但在使用中肯定有一些偏好。美式英语和英式英语的三个主要区别是：

Pronunciation - differences in both vowel and consonants, as well as stress and intonation
发音-元音和辅音的差异，以及重音和语调

Vocabulary - differences in nouns and verbs, especially phrasal verb usage and the names of specific tools or items
词汇.名词和动词的区别，特别是短语动词的用法和特定工具或项目的名称

Spelling - differences are generally found in certain prefix and suffix forms
拼写-在某些前缀和后缀形式中通常会发现差异

The most important rule of thumb is to try to be consistent in your usage. If you decide that you want to use American English, then be consistent in your spelling (i.e. "The color of the orange is also its flavour" - color is American spelling and flavour is British). Of course, this is not always easy or possible. The following guide is meant to point out the principal differences between these two varieties of English.
最重要的经验法则是在使用中保持一致。如果你决定使用美式英语，那么你的拼写要一致（即“橙色也是它的味道”——color是美式拼写，flavour却是英式）。当然，这并不总是容易或可能的。下面的指南旨在指出这两种英语的主要区别。

Minor Grammar Differences
语法上的细小差异

There are very few grammar differences between American and British English. Certainly, the words we choose might be different at times. However, generally speaking, we follow the same grammar rules. With that said, there are a few differences.
美式英语和英式英语几乎没有语法差异。当然，我们选择的词有时可能会有所不同。但是，一般来说，我们遵循相同的语法规则。尽管如此，还是有一些不同之处。

Use of the Present Perfect
现在完成时的用法

In British English, the present perfect is used to express an action that has occurred in the recent past that has an effect on the present moment. For example:
在英式英语中，现在完成语是用来表达最近发生的、对现在产生影响的动作。例如：

I've lost my key. Can you help me look for it?
我的钥匙丢了。你能帮我找一下吗？

In American English, the following is also possible:
在美式英语中，也可能出现以下情况：

I lost my key. Can you help me look for it?
我把钥匙丢了。你能帮我找一下吗？

In British English, the above would be considered incorrect. However, both forms are generally accepted in standard American English. Other differences involving the use of the present perfect in British English and simple past in American English include already, just and yet.
在英国英语中，上述内容被认为是错误的。然而，这两种形式都是标准美式英语。在英式英语中使用现在完成时和在美国英语中使用简单过去语的其他差异包括“已经”、“刚刚”和“尚未”。

British English:
英式英语

I've just had lunch.
我刚吃过午饭。

I've already seen that film.
我已经看过那部电影了。

Have you finished your homework yet?
你做完作业了吗？

American English:
美式英语：

I just had lunch OR I've just had lunch.
我刚吃过午饭或刚刚吃过午饭。

I've already seen that film OR I already saw that film.
我已经看过那部电影了。

Have you finished your homework yet? OR Did you finish your homework yet?
你做完作业了吗？

Two Forms to Express Possession
两种表示占有的形式

There are two forms to express possession in English: have or have got.
用英语表达占有有两种形式：有或有。

Do you have a car?
你有车吗？

Have you got a car?
你有车吗？

He hasn't got any friends.
他没有朋友。

He doesn't have any friends.
他没有朋友。

She has a beautiful new home.
她有一个漂亮的新家。

She's got a beautiful new home.
她有一个漂亮的新家。

While both forms are correct (and accepted in both British and American English), have got (have you got, he hasn't got, etc.) is generally the preferred form in British English, while most speakers of American English employ the have (do you have, he doesn't have etc.)
虽然这两种形式都是正确的（在英国和美国英语中都被接受），但是got（你有，他没有，等等）通常是英国英语中的首选形式，而大多数说美国英语的人都使用have（你有，他没有等等）。

The Verb Get
关于动词get

The past participle of the verb get is gotten in American English.
动词get的过去分词是用美式英语来表示的。

American English: He's gotten much better at playing tennis.
美式英语：他网球打得好多了。

British English: He's got much better at playing tennis.
英式英语：他网球打得好多了。

"Have got" is used predominately in British English to indicate "have" in the sense of possession. Strangely, this form is also used in the United States with the British participle "got," rather than "gotten." Americans will also use "have got to" in the sense of "have to" for responsibilities.
“have got”在英国英语中主要用于表示“have”的占有意义。奇怪的是，这种形式在美国也是用英国分词“got”而不是“got”来表示的，美国人也会用“have got to”来表示“必须”的责任。

I've got to work tomorrow.
我明天得工作。

I've got three friends in Dallas.
我在达拉斯有三个朋友。

Vocabulary
词汇

The largest differences between British and American English lie in the choice of vocabulary. Some words mean different things in the two varieties, for example:
英式英语和美式英语最大的区别在于词汇的选择。有些词在这两个变体中的含义不同，例如：

Mean: American English - angry, bad humored, British English - not generous, tight-fisted.
mean的含义：美式英语-愤怒，不幽默，英式英语-不慷慨，握紧拳头。

American English: Don't be so mean to your sister!
美式英语：别对你姐姐那么刻薄！

British English: She's so mean she won't even pay for a cup of tea.
英式英语：她太吝啬了，连一杯茶都不付钱。

There are many more examples (too many for me to list here). If there is a difference in usage, your dictionary will note the different meanings in its definition of the term. Many vocabulary items are also used in one form and not in the other. One of the best examples of this is the terminology used for automobiles.
还有更多的例子（我在这里列举的例子太多了）。如果在用法上有差异，你的词典将在其术语定义中注明不同的含义。许多词汇项也以一种形式使用，而不是以另一种形式使用。其中一个最好的例子就是汽车术语。

American English - hood / British English - bonnet
美式英语-引擎盖hood/英式英语-引擎盖bonnet

American English - trunk / British English - boot
美式英语-后备箱trunk/英式英语-后备箱boot

American English - truck / British English - lorry
美式英语-卡车truck/英式英语-卡车lorry

For a more complete list of the vocabulary differences between British and American English, use this British vs. American English vocabulary tool.
为了更完整地列出英式英语和美式英语之间的词汇差异，请使用这个英式和美式英语词汇工具。

Spelling
拼写

Here are some general differences between British and American spellings:
以下是英式拼写和美式拼写之间的一些一般差异：

Examples of words that end in -or in American English and -our in British English: color/colour, humor/humour, flavor/flavour
以美国英语和英国英语结尾的单词示例：颜色/颜色、幽默/幽默、风味/味道

Examples of words that end in -ize in American English and -ise in British English: recognize/recognise, patronize/patronise
美国英语和英国英语中以-ise结尾的单词示例：识别/识别、惠顾/惠顾

The best way to make sure that you are being consistent in your spelling is to utilize the spell check tool associated with your word processor and select the type of English (American or British) you'd like to use.
确保拼写一致的最佳方法是使用与文字处理程序相关联的拼写检查工具，并选择要使用的英语类型（美国或英国）。