解放军文职考试英语辅导：was和is的区别

二者时态不同，is是一般现在时态，was是过去时态。二者用法不同，“现在时间”用is，“过去时间”用was。be动词的形式有am，is，are，been，being，was，were。

be（be/is/are/am/was/were)[bi:]vi

he is, we are, you are, they are （缩略式 I'm, you're, he's, we're, you're, they're）, （否定缩略式 I'm not, isn't, aren't）, 过去时 I was, you were, he was, we were, you were, they were （过去时否定缩略式 wasn't, weren't）,过去分词been,现在分词being

“Be”除了原形的“be”之外，还有另外七种形式：am, is, are, been, being, was, were.

在句子中，“be”可以是主动词(The Principal Verb)或助动词(The Auxiliary Verb)

例句对照

当做主动词时，“be”在性质上属于接系动词(The Linking Verb), 后面要有名词、形容词、地方副词或短语作补足语(The Complement)。例如：

The man is a science teacher.

这个男子是一位科学教师。

Mary's new dresses are colourful.

玛丽的新衣服色彩鲜艳。

I have been there before.

我以前去过那里。