somewhere和someplace有什么区别?请说的具体一些,特别是在句子中有什么区别?

somewhere 词义和词性比较广泛.副词 ad.
1.在某处;到某处
Come and see me then.We'll go out somewhere.
那你来看我吧,我们一起到外面什么地方玩玩.
2.在某个时候
It happened somewhere in the 18th century.
这事发生在十八世纪某个时候.
3.大约,大概
He was a thinnish fellow,somewhere in his forties.
他瘦瘦的,大约四十多岁.
名词 n.某个地方;某个方面
We must look for somewhere to live.
我们必须找个地方住下.
someplace 副词 ad.在某处;到某处
You must have left the keys someplace else.你一定是把钥匙落在别的什么地方了.

somewhere是副词，使用时不加介词。someplace是名词，前面是做状语要加介词