I go to school. "to school"是介词短语，作状语修饰 go。
It is a book on the desk.
I have a T-shirt in red. ”in red“ 是介词短语，作为定语修饰T-shirt.
I go to school. 很好理解。
I go home. ??? 这是什么玩意？
I go my home. 这就错了，因为my home 的”home“是个名词了,必须写成I go to my home.
that which who whom whose
This is a carrot that i bought. 其实是I bought that,把that提到句首。
The rabbit ate the largest carrot that I’ve ever seen.largest是最大的，所以是唯一的，用that.
除了the largst以外，all/the only/the first这种修饰语也是代表不可选的，用that。
The rabbit ate a carrot which i bought. 这里的carrot就可以是多个，多选一的，用which
where why when whether 等
where=at/on/in which why=for which when=at/on/in which
The rabbit ate the carrot which was on the table.兔子吃了在桌上的胡萝卜
"which was on the table"限定了carrot,重点在说明(限定)是carrot是指桌上的carrot
The rabbit ate the carrot,which was on the table.兔子吃了胡萝卜，胡萝卜在桌上。
I have a head which is round. 我有一个圆圆的头（暗指我可能还有扁的头，方的头，这只是其中一个）
I have a head, which is round.我有一个头，它是圆的。
That rabbit eate carrot is obvious.
What rabbit eate is obvious.
where rabbit eate is obvious.
I saw that the rabbit ate a carrot.
I didi’t know that the rabbit ate the carrot and
that you saw it.
I saw what the rabbit ate.
I saw where the rabbit ate.
I am sure/afraid/happy that there is a carrot on the table.
The problem is that the rabbit is hungry.
The question is what the rabbit should eat.
The question is wehre/when/how the rabbit should eat.
The fact that the rabbit ate teh carrot did not surpprise me.
相当于：The fact, the rabbit ate teh carrot, did not surpprise me.
I have no idea who ate the carrot.
you can call me what you like.
before / after
when / while / as
since / until / as soon as / the next time
where / wherever / anywhere /
The rabbit ate the carrot where he found it.（这是状语从句）
The rabbit ate the carrot at the place where he found it.(这是定语从句)
than / as …as / the …the
he is smarter than i am.
常被省略成：he is smarter than i.
口语化一般为：he is smarter than me.
This carrot is bigger than that one is.
省略：This carrot is bigger than that one.
He is as smart as i am.
This carrot is as big as that one is.
He is as smart as me.(口语化了，本来是I)
This carrot is as big as thet one.
The more you practice English,the more fluent you become.
if / unless / provided / as long as / in case
If the rabbit sees a carrot,he will eat it.
if i saw a carrot,I would eat it. (这是虚拟语气，不是条件状语从句)
if i had seen a carrot,I would have eaten it.(这是虚拟语气，不是条件状语从句)
even / even if / although / no matter how/what / regardless of
Although I see a carrot,but I will not eat it.这里得把but去掉，因为although引导一个从句，而but是个连词，后应该接一个句子，而不是主句。
as if / as
because / since / as
Since you are hungry,you can eat teh carrot. 既然你饿了，你可以吃胡萝卜。
As I have thick skin,I am begging you for a thumbs up.显而易见…
you must really like me,for you have given all my cideos a thmbs-up.这里的for是个连词。
in order…so that / in order to/that
so that / so/such…that