is后面的动词一定要用ing,但是也要具体情况具体分析的,当为be+to do 为将要做某事,或是祈使句。例如:What you've got to do is turn around and say :" Watch me"。为一句祈使句。
系动词Be(am, is, are)的用法
1.基本形式:am、are、is
(1)、am
第一人称I+am (注意:“I”无论何时都要大写,不管位于句首还是句中)
例:I am a beautiful girl. I am twenty.
I am 还可缩写成I'm。 如:I'm David. 我是大卫。
但是am与not不能缩写。
(2)、are
第二人称you+are; 一人称复数we+are; 三人称复数they+are 其他复数名词+are
(注意:第二人称单复数同形,都为you)
例:You are my good friend. We are in the same class.
They are on the road. The books are on the desk.
are与主语还可缩写。如:
We are= We're, They are =They're, You are = You're。而are与 not可缩写成aren't。
(3)、is
第三人称he(男) +is ; she(女)+is; it(不是人)+is;其他单数名词+is
例:He\She is a good student. It is a white cat. A dog is on that street.
is也可与主语缩写,如:
He is = He's, My mother is = My mother's等。但是This is不可缩写。而is与not可缩写成 isn't。
如:This isn't a book. 这不是一本书。
2.请记住以下口诀:
我用am,你用are,is连着他,她,它;
单数名词用is,复数名词全用are。
变疑问,往前提,句末问号莫丢弃。
变否定,更容易,be后not莫忘记。
疑问否定任你变,句首Am,Is,Are大写莫迟疑,,句末问号莫忘加