英语复数句怎么变单数句
变法是把能变成单数的词变成单数，复数代词变为单数代词，句子中的复数名词变为单数名词。能加a或an的句子把a或an加上。特殊疑问词、形容词、国家及地点通常不变。介词短语中的名词不变。
be动词：are-is，am
扩展资料
一、绝大多数的可数名词的复数形式，是在该词末尾加上后辍-s。
例：friend-friends，cat-ats，style-styles，sport-sports，piece-pieces
二、凡是以s、z、x、ch、sh结尾的词，在该词末尾加上后辍-es构成复数。
例：bus-buses，quiz-quizzes，fox-foxes，match-matches，flash-flashes
三、以辅音字母+y结尾的名词，将y改变为i，再加-es。
例：candy-candies，daisy-daisies，fairy-fairies，lady-ladies，story-stories
四、以-o结尾的名词，如果不是外来词或缩写，就加-es，否则加-s构成复数。
例：tomato-tomatoes，potato-potatoes，torpedo-torpedoes，bingo-bingoes
反例：silo-silos，piano-pianos（外来词），photo-photos，macro-macros（缩写词）
五、以-f或-fe结尾的名词，多为将-f或-fe改变为-ves，但有例外。
例：knife-knives，life-lives，leaf-leaves，staff-staves，scarf-scarves
反例：roof-roofs
复数变单数还是单数变复数，有be动词的就是be动词的变化,一般情况下就是is（was）和are（were）之间的转变,单数用is（was），复数用are（were）。
一般现在时，主语是第一（I）、二（you）人称的用do，第三（he she it）人称用does；正在进行时，把be动词提前就可以，首字母大写，后加问号；一般过去式，无人称区别,都用did；一般将来时，第一人称用shall，第二、三人称用will,也可以都用will。
扩展资料：
复数的规则：
（1）元音字母和大多数除s,z,x,sh,ch之外的辅音字母直接加-s,清辅音后的s读作/s/ ，元音和浊辅音后的s读作/z/。如：bag-bags,biscuit-biscuits,egg-eggs.
当单数名词结尾为se，ze，ge，ce时（其词尾辅音为/s，z，ʃ，ʒ/等），加s后读作/iz/。如vase-vases，fridge-fridges
（2）当单数名词结尾为s,z,x,sh,软音ch时（其词尾辅音为/s，z，ʃ，ʒ/等）加-es（读/iz/）, 如：box-boxes, peach-peaches. (o有时也是，但es读音为/z/如hero-heroes)例外：stomach-stomachs（因ch读作/k/）
人称,指示,反身变 物主代词看一看.
连系动词 am is 变成 are.
冠词a an要去掉,改为some,any也可以.
名词做定语,介宾不要变；有man和woman也例外.
句式不要变,十全十美题做完.
1人称代词由单数变复数： 1 主格 I we ,you you ,he/she/it they . 2 宾格me us ,you you ,him/her/it them . 例1 She is a girl . They are girls . 例2 I like her. We like them.2 指示代词由单数变复数： this these , that those 例1 This is a book . These are（some）books . 例2 Is that a pen? Are those（any）pens?
3 反身代词：
第一人称 myself ourselves
第二人称 yourself yourselves
第三人称 himself themselves
( herself, itself ) 例1 I am teaching myself computer. We are teaching ourself computer.
例2 The child himself draws this picture. The children themselves draw these pictures.
4 物主代词由单数变复数： 1 名词性物主代词：mine ours ,yours yours , his/hers/its theirs 2 形容词性物主代词：my our,your your , his/her/its their 例1 The book is mine. The books are ours. 例2 This is her pen. These are their pens.
5 一般情况下,形容词性物主代词在单数句变复数句时不变. 例1 This is my book . These are my books . 6 当句中形容词性物主代词与句中的主语一致时,形容词性物主代词 应随主语人称的变化而变化, 仍要保持一致. 例1 He likes his bike. They like their bikes.
7 连系动词由单数变复数 ：is/am are 例1 I am a teacher. We are（some） teachers. 8 a/an表示一个,只能用在单数名词前,当单数句变复数句时, 一定要把a/an去掉,或改为some/any. 例1 This is a book . These are（some）books . 例2 Is that a pen? Are those（any）pens? 9 当名词作定语或在介词短语中作介词宾语充当除宾语以外的 其它成分时, 该名词不变. 例1 He is a boy student .They are（some）boy students. （man和woman）除外. 例2 She is a woman worker. They are（some）women workers.
10 单数句变为复数句时,句式不能改变,即单数句是疑问句时, 变为复数句时,仍然是疑问句. 例1 What’s this? What are these? 例2 She likes his bike. They like their bikes. 可数名词的复数形式的部分规则 1 一般情况加s,结尾是清辅音读[s],结尾是浊辅音或元音读[z]. 例：friend→friends; cat→cats; style→styles; sport→sports; piece→pieces 2 以s、x、ch、sh结尾的词,在该词末尾加上后辍-es构成复数. 读[iz]. 例：bus→buses; quiz→quizzes; fox→foxes; match→matches; flash→flashes 3 以辅音字母+y结尾的名词,将y改变为i,再加-es. 读[z]. 例：candy→candies; daisy→daisies; fairy→fairies; lady→ladies; story→stories 4 以-o结尾的名词,有生命的加-es,无生命的加-s构成复数. 读[z]. 例：tomato→tomatoes; potato→potatoes; torpedo→torpedoes;bingo→bingoes （有生命） 例：silo→silos; piano→pianos; photo→photos; macro→macros（无生命） 5 以-f或-fe结尾的名词,多为将-f或-fe改变为-ves,但有例外. 读音变化：尾音[f]改读[vz]. 例：knife→knives; life→lives; leaf→leaves; staff→staves; scarf→scarves 反例：roof→roofs 6 以-ce se ze（d）ge等结尾的名词,加-s,读[z]. 例price—prices case—cases orange—oranges 名词的不规则变化： man→men; woman→women; child→children; people→people; fish→fish; sheep→sheep; deer→deer; foot→feet; mouse→mice; tooth→teeth; 单数句变复数句精炼一 将下列单数句变为复数句 1 This is a book . 2 Is that a pen? 3 She is a girl . 4 I like her. 5 The book is mine. 6 This is her pen. 7 I am a teacher. 8 He is a boy student . 9 She is a woman worker. 10 He likes his bike.二 将下列复数句变为单数句 1 What are these? 2 They like their bikes. 3 These are my books . 4 These are（some）books . 5 Are those（any）pens? 6 They are girls . 7 We like them. 8 These are（some）books . 9 Are those（any）pens? 10They like my bikes.三 将下列名词变为复数形式 map egg apple orange pen box bus girl boy baby knife photo tomato man woman milk water desk table bike 单数句变复数句精炼答案一 将下列单数句变为复数句 1 These are（some）books . 2 Are those（any）pens? 3 They are girls . 4 We like them. 5 The books are ours. 6 These are their pens. 7 We are（some） teachers. 8 They are（some）boy students. 9 They are（some）women workers. 10 They like their bikes. 二 将下列复数句变为单数句 1 What is this? 2 He likes his bike 3 This is my book . 4 This is a book . 5 Is that a pen? 6 She is a girl . 7 I like her. 8 This is a book .. 9 Is that a pen? 10 He likes my bike.三 将下列名词变为复数形式 maps eggs apples oranges pens boxes buses girls boys babies knives photos tomatoes men women milk water desks tables bikes
首先看主语，谓语，其次是表语或宾语，以及其他成分
将作主语的主格人称代词,由单数形式变为复数形式,即:I→we,you→you,she(he,it)→they。
谓语和be 动词也要从复数形式变成相应单数形式，即 are 和is/am ,were和was，do和does等。
宾语也要从复数形式转化为单数，比如 bags,apples,students等。
举个例子吧
These are bags.
主语为指示代词these , 谓语是are ,表语是bags
分别找出其相应的单数
these---this are ----is bags----bag
所以这个句子变成单数句可以这样写：This is a bag.
如果是复杂的句子也可以把句子的每个成分变成单数，只要掌握名词单变复的规则,注意主谓一致就好了。
