否定句
否定句的结构是：与陈述句相同，但谓语要用否定形式。
肯定句变否定句时应注意：
句子中谓语是系动词、情态动词或含有助动词，将系动词或助动词变成否定形式。如：
He's a headmaster.→He isn't a headmaster.
John will visit the museum.→John won't visit the museum.
谓语是实义动词(包括do)，则须加助动词do(does),did的否定形式。如：
Henry works in a hospital.→Henry doesn't work in a hospital.
The old man does morning exercises behind the building.→The old man doesn't do morning exercises behind the building.
句中有否定词never,little,hardly,nobody,nothing,few,none,neither...nor等词时，该句就是否定句，再不能将该句变为否定句了。
在一般情况下，肯定句在变否定句后，some,something,already分别要变为any,anything,yet。如：
He bought some fruit in the shop.→He didn't buy any fruit in the the shop.
We've already planted the trees.→We haven't planted the trees yet.
但一些含some的动词短语作谓语时，some不能变any。如：
The girl did some washing last Sunday.→The girl didn't do some washing last Sunday.
句子中有表示全部概念的词或短语，如all，both，always，everybody，everything等词时，要把all改为none of;both改为neither of;always改为never;everybody改为nobody;everything改为nothing。如果改变后的代词在句子当中作主语，要注意谓语的数。如：
They're both at work.→Neither of them is at work.
She always helps me.→She never helps me.
Everybody left.→Nobody left.
在主句谓语动词是think，feel，believe(相信)的复合句中，如果要否定从句，英语句子则要否定主句。如：
I think he'll come today.→I don't think he'll come today.
He felt their team would win.→He didn't feel their team would win.
练习：
在每个空白处填写一个适当的词，使该句变成否定句。
1.We'll visit a few places of interest this weekend.
We visit a few places of interest this weekend.
2.The farmers pick apples in autumn.
The farmers apples in autumn.
3.Lily threw a stone through the window.
Lily a stone through the window.
4.We can see something in the dark room.
We in the dark room.
5.We all like playing pingpong.
playing pingpong.
答案与分析：
1.该句谓语是will visit,因此在变否定句时，将will变成won't。
2.该句谓语是pick,故须在pick前加don't，即填写don't pick。
3.该句谓语是threw,所以应加didn't，并将threw变成原形。应填写didn't throw。
4.该句谓语是can see,而且句中有something。因此，应将can变成can't see;something变成anything。
5.该句谓语是like,而且句中有all。因此，应填None of us likes。
