1.是Thisisapairofglasses还是Theyapairofglasses2.是Thisistwoglassesofjuice还是Theyaretwoglassesofjuice.我想问的是比如一双袜子、一副眼镜（可数名词）时前面是用is还是are,比如两杯果汁时（不

Question

1.是This is a pair of glasses 还是They a pair of glasses
2.是This is two glasses of juice还是They are two glasses of juice.
我想问的是比如一双袜子、一副眼镜（可数名词）时前面是用is 还是are,比如两杯果汁时（不可数名词）前面是用is还是are?
3.为什么what size shoes没有of来连接shoes,而what size of dessert有of来连接呢?
4.为什么可以the bag is 8 yuan ,也可以we have bags for 8 yuan.是不是用for连接价格时前面会有动词,比如have.
第一个问题应该是是This is a pair of glasses 还是They are a pair of glasses

Answer 1

1.a pair of 当单数用,比如 a pair of shoes,就用this is
2.this 对应的不是 they,而是 these are two glasses of juice
用单复数主要是看量词,比如two glasses of water就要用复数,而 a glass of water 就用单数.
3.what size shoes不能单独用,单独用要用what size of shoes,--- 鞋子多大?
具体用在句子里面比如：What size shoes do you wear?这里size是形容词,来修饰shoes
后面的dessert前面用of的意思是---多大的甜点,和第一个用法相同.
4.we have bags for 8 yuan.for 8 yuan是宾语补足语,前面是个主谓宾的句子.你说的应该对,这种句子在for引导的宾补才用.比如 I bought a chair for only 5 RMB.