There was a piece of cloth tied to the dog"s collar.有一條布系在狗項圈上.
4.(表示方位) 在
Hemingway"s studio is to the right.海明威的工作室在右邊.
5.給 [用法v+n+to+n]
He picked up the knife and gave it to me.他撿起刀並拿給我.
6.(表示行為或情感針對的目標) 對於 [用法：adj/n+to+n]
Marcus has been really mean to me today.馬庫斯今天確實一直對我不友好.
7.對 (表示受某事影響) [用法：adj/n+to+n]
He is a witty man,and an inspiration to all of us.他是一個風趣的男人,對我們所有的人是一種鼓舞.
8.對… (說)
I will explain to them that I can"t pay them.我會向他們解釋說我無法付錢給他們.
9.(表示反應或情感) 致使
To his surprise,the bedroom door was locked.使他吃驚的是,臥室的門是鎖著的.
10.在…看來
It was clear to me that he respected his boss.在我看來,顯然他尊重他的老闆.
11.(表示狀態或形勢等的變化) 成為
The shouts changed to laughter.叫喊聲變成了笑聲.
to還有不做介詞的情況,比較少：
If you say "There"s nothing to it," "There"s not much to it," or "That"s all there is to it," you are emphasizing how simple you think something is.(表示強調) 容易得很
to後面的動詞為現在進行時的話to就是介詞； to加名詞/動名詞(那不是現在進行時) 就是介詞；另外,有的是固定片語（比如look forward to的to就是介詞。
to後面加動詞原形為不定式。
例，
TO做介詞的用法：
1.(表示方向、目的地) 向
She went to the window and looked out.她走到窗前向外望去.
2.去 (參加)
He came to dinner.他來吃晚飯.
3.附著
There was a piece of cloth tied to the dog"s collar.有一條布系在狗項圈上.
4.(表示方位) 在
Hemingway"s studio is to the right.海明威的工作室在右邊.
5.給 [用法v+n+to+n]
He picked up the knife and gave it to me.他撿起刀並拿給我.
6.(表示行為或情感針對的目標) 對於 [用法：adj/n+to+n]
Marcus has been really mean to me today.馬庫斯今天確實一直對我不友好.
7.對 (表示受某事影響) [用法：adj/n+to+n]
He is a witty man,and an inspiration to all of us.他是一個風趣的男人,對我們所有的人是一種鼓舞.
8.對… (說)
I will explain to them that I can"t pay them.我會向他們解釋說我無法付錢給他們.
9.(表示反應或情感) 致使
To his surprise,the bedroom door was locked.使他吃驚的是,臥室的門是鎖著的.
10.在…看來
It was clear to me that he respected his boss.在我看來,顯然他尊重他的老闆.
11.(表示狀態或形勢等的變化) 成為
The shouts changed to laughter.叫喊聲變成了笑聲.
to還有不做介詞的情況,比較少：
If you say "There"s nothing to it," "There"s not much to it," or "That"s all there is to it," you are emphasizing how simple you think something is.(表示強調) 容易得很