in / at有咩分別? 應該點用?

最基本概念係:大嘅地方係 in 例如:country.
細嘅地方係 at 例如: school.
in 係長時間　例如: in 2008.
at　係短時間　例如:　at seven o'clock.
in是否代表在某個時間入面?
at是否代表在某一個地方?

其實唔一定
in home在家中
Old people prefer to stay in their own homes.
=at home在家
at the corner of the street
at the airport
at the hospital
at the bank
at the concert(音樂會上）
at the end of the week(週末）
at the time(在．．．．的時候）
in 2008
in the 20th century
in spring
in March
in the morning
at the weekends
in old age(上左年紀）
at the age of 1６(１６歲)
in the street(在街上）
at street level=on the ground floor
in time(及時）
at times=sometimes