英语语法
4.单复数同形。如：
sheep---sheep deer---deer
fish---fish people---people
5.表示“某国人”的单、复数变化。即“中日瑞不变英法变，其它国把-s加后面”。如：
Chinese---Chinese Japanese---Japanese Swiss---Swiss
Englishman---Englishmen Frenchman---Frenchmen
American---Americans Australian---Australians
Canadian---Canadians Korean---Koreans
Russian---Russians Indian---Indians
6.其它。如：
mouse---mice
apple tree---apple trees
man teacher---men teachers
14) 双写最后一个字母的-ing分词
初中阶段常见的有以下这些：
1.let→letting 让 hit→hitting 打、撞
cut→cutting 切、割 get→getting 取、得到
sit→sitting 坐 forget→forgetting 忘记
put→putting 放 set→setting 设置
babysit→babysitting 临时受雇照顾婴儿
2.shop→shopping 购物 trip→tripping 绊
stop→stopping 停止 drop→dropping 放弃
3.travel→travel(l)ing 旅游 swim→swimming 游泳
run→running 跑步 dig→digging 挖、掘
begin→beginning 开始 prefer→preferring 宁愿
plan→planning 计划
15) 肯定句变否定句及疑问句要变化的一些词
1.some变为any。如：
There are some birds in the tree.→There aren't any birds in the tree.
但是，若在表示请邀请、请求的句子中，some可以不变。如：
Would you like some orange juice?
与此相关的一些不定代词如something, somebody等也要进行相应变化。
2.and变为or。如：
I have a knife and a ruler.→I don't have a knife or a ruler.
3.a lot of (=lots of)变为many或much。如：
They have a lot of friends.（可数名词）→They don't have many friends.
There is lots of orange in the bottle.（不可数名词）
→There isn't much orange in the bottle.
4.already变为yet。如：
I have been there already.→I haven't been there yet.
16) in与after
in 与 after 都可以表示时间，但二者有所区别。
1.in 经常用于将来时的句子中，以现在为起点，表示将来一段时间。如：
