表示时间的区别：

at指时间表示：

1）时间的一点，一时刻：

They come home at surprise (at noon, at midnight, at ten o’clock, at daybreak, at dawn).

2) 较短的一段时间。可指某个节日或认为一年中标志大事的日子。

His grandfather died at seventy-two.

At the beginning (middle, end) of that month he was sick.

He went home at Christmas (at New Year, at the spring Festival, at night, at midsummer).

in指时间表示：

1）在某个较长的时间（如世纪，朝代，年，月，季节，及泛指的上午，下午和晚上等）内。

He died in the holidays.

He was born in 1942.

2) 在一段时间之后。

He will come round in a day or two.

I will finish it in three hours.

on指时间表示：

1）具体的时日和一个特定的时间，如某日，某节日，星期几等。

He will come to meet us on our arrival.

On May 4th (On Sunday, On New Year’s day, On Christmas Day), there will be a celebration.

2) 在某个特定的早晨，下午或晚上。

He arrived at 10 o’clock on the night of the 5th.

He died on the eve of victory.

3) 准时，按时。

If the rain should be on time, I should reach home before dark.

表示地点的区别

in 表示地点

1) in 表示比较大的地方，

2)虽然是很小的地方，如果说话人住在那里，也可用in.商店，机关，学校等，若看作一个地点（point)用at,若看作一个场所（place)用in.

I met him at the post-office.

I’m now working in the post-office.

On表示地点

一般指与面或线接触：

1）“在…上面”

He put the book on the table and sat on the chair.

The picture was hanging on the wall.

2) “在…… 旁边”

New work is on the Hudson River.

Xiamen is on the river.

He lives in a house on the river.

1). near, by, beside, at表示“在•••••••附近”的区别：

near 表示相对的“近”，实际距离可能还很远。

例如： There is a post office near our school. Suzhou is near Shanghai.

By和beside都表示“靠近”，实际距离不可能很远，但beside比by更具体的表示出“在•••••••旁边”的意思。

例如：

There is a big tree by the river.

He was sitting beside her.

by还可以表示“尺寸，距离”。

例如：

They escaped death by inches.

Do you see the hole high up in the wall, about 18 cm by 9?