on at in

I am confused about the "on", "in" and "at", anyone tell me how to distinguish them clearly.

They're not easy. How to distinguish them clearly is to look at and listen to a huge number of examples.

Exactly.

Tidus

Learn them in a an examples :

I'll be with you 'in' a moment.
I asked my brother to tidy up, but 'in' the end I had to do it myself.
I'll post the letter 'on' the way back.
Immigration officers inspected his passport and everything was 'in' order.
There's a big picture of W. Bush 'on' the front page of this morning's paper.
'at' the end of the week
I'll be 'at' home all the morning.
I was 'at' my uncle's.
She works 'at' the hospital.

Sorry, in examples

On: means to be atop of said object. "I sat 'on' a chair"

In: means to be inside of said object. "I sit 'in' my car"

At: means to be in a specific place: "I arrived 'at' the train station"

Most variations are a slang and use the words as almost a metaphor.

"I arrived 'on' time" obviously I cannot stand upon time. so 'on' refers to the fact that I have accomplished my goal of arriving quickly.


I hope I did not confused you?

It's really more complicated than atop vs. inside, and this is one place I wouldn't bother with trying to learn a rule but rather just jot down every occurence you come across.

Consider: "I like relaxing in a comfortable chair."
(not "on", but "in", even though I'm not inside the chair)

"Lance Armstrong is riding comfortably in the saddle." (similarly; he's atop it, not inside it, but you never say "on the saddle", contrary to all logic.)

"I ride to work on the bus" (though I'm most likely inside it, not atop it)

but "I ride to work in my car."

"I ride my bike on the highway" but "I ride in the rightmost lane of the highway."

"I'm in my office" and "I'm at my office" are both fine and pretty much interchangable, but "I'm at work" is correct and "I'm in work" is wrong. On the other hand, "I'm on the job" (but never "in the job" and probably never "at the job.")

"He's at Steve's house", "He's at Steve's", and "He's in Steve's house"
are all legitimate, but "He's in Steve's" is no good.

How about time expressions? "In the morning", "At sunrise", "On the first of the month", "At Christmastime". There's no rationale, it just is what it is.

Not to mention sporadic, weird examples like "I'm in the way" vs. "I'm on the way."