英语常识!there they their those these that this 有什么区别,分别在什么情况下使用

there 一般都是 there be 的句型比较多:
There is an apple on the table.
There are some apples on the table.
There is an apple and two pears on the table.
or
There are two pears and an apple on the table.
主要是看前面是单数还是复数,前面是单数就用there is,前面是复数就用there are
they 是主格一般用于句子开头
They are good students.
What are they?
their 是他(她它)们的意思是形容词性物主代词
Their bags are big.
those 是那些 these 是这些
that 是那个 this 是这个
thosethese 用于复数(同their)
thatthis 用于单数
That is a good idea.This book is mine.
介词+动词ING
What about going(...ing) for a walk in the park?
Thank you for helping me.
副词用来修饰动词的
She dances beautifully.
He walks carefully.
I'm doing sth.
I'm Peter.(人名)
I'm tall.(形容词)
I'm from China.
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