一般in表示在某個空間內,而inside還有掩蓋、受保護的意思.
inside是語氣很強的介詞.它常用來強調某 人或某事所在地含有某種特殊情況,比如：Inside the castle we'll be safe from the enemy.在上句中,說話人可能想到的是城堡上厚厚的城墻,或城堡是一個非常堅固的地方.當然,某人 也能把一個相當普通的地方說成是一個牢不可破 的堡壘,比如：He barricaded himself inside the house and started firing at the police.
有時說話人想強調某個地方的空間非常狹窄,比如：It was hot and stuffy inside the prison cell.
inside也可用于與外面的事情(something outside) 作對比：It was quite hot outside the cave but when we were inside,we started to shiver.
除需要特別強調以外,通常都用in.例如,用于建筑物或建筑物內的房間：in the house,in the office; 用于有圍欄或圍墻的地方：in the garden,in the courtyard,in the park; 用于交通工具：in the train,in the car,in the bus; 用于江河湖海：in teh sea,in the river,in teh water.還可用于飲料,如：There's a fly in my lemonade.
盡管人們在 There may be beetles in the lawn 或in the carpet中用in,但是在One sits on the lawn或on the carpet中卻要用on.
當談到服裝時,用in和用inside在句子意思 上就出現(xiàn)了有趣的區(qū)別.通常用in.
但是,人穿著衣裳感到不舒適或感到受到約束(如 同身處囹圄),這時用inside 就會非常生動有效地 表達此種感覺,例如：
The little girl felt like a prisoner inside her starched new dress.Mary felt like a packaged chicken inside her corsets.
當然,有時用in和inside都不合適,例如：She was kept in/inside the walls of the prison.
此句的意思是她和水泥一起被填進了墻里.這種 情況可能有,但是不會經常出現(xiàn).是不是in表示沒有完全覆蓋，而inside卻表示完全覆蓋了