1、时间介词 in,on,at
at < 天 (eg.noon,dawn,night,one’ clock)
on = 天 (Monday,30th June,New Year’s Day,Mother’s Day）
in > 天 (2008,summer,April,还有早午晚)
注意：
1) 早午晚前后如有修饰语则用 “on”
On Monday morning
On a sunny afternoon
On the morning of May 23rd
On a dark night
2) on,in,at不用于下列时间之前：this,that,last,next,every,each,today,yesterday,tomorrow,tonight
3) in+一段时间可以表“…之后”
Eg:Hurry!The school bus will leave in five minutes
I will see my grandparents in a few days.
2、方位介词：
1）at和in
in 大地点 ≥town
at 小地点 < town
eg.:in town at bus station
in Beijing at school
in USA
2）on表示在物体表面上 eg:on the table ,on the wall
注意：1) on the tree 长在树上 There is an apple on the tree.
in the tree 呆在树上 There is a bird in the tree.
2）on the wall 挂在墙上 There is a picture on the wall.
in the wall 嵌在强中 There is a window in the wall.