What's the proper way to use 先 versus 前に or 以前?


I'm trying to understand why 先 is not the best choice to use in these
sentences. Is it wrong to use it in this way?

× 先、学校で何かが起こった。  
○ 以前、学校で何かが起こった。

× 先の書いた本から十年間が過ぎました。  
○ 前に書いた本から十年間が過ぎました。




I'm going to assume you mean 先 as in さっき. It's usually written in hiragana to
avoid confusion.

I think the first sentences are just fine. The × one sounds like spoken
language and ○ one sounds more like written language.

In the second × sentence, though, さっき would not work because it's used for
things that happened "just now" and ten years ago is not "just now". Also, the
の there is not correct, it's only used when さっき is used to modify a noun or a
noun-phrase. You could say e.g.「さっき書いたメール」 for "an e-mail [I] wrote just now"
though.




I'm going to assume you mean 先 as in さっき. It's usually written in hiragana to
avoid confusion.

I think the first sentences are just fine. The × one sounds like spoken
language and ○ one sounds more like written language.

In the second × sentence, though, さっき would not work because it's used for
things that happened "just now" and ten years ago is not "just now". Also, the
の there is not correct, it's only used when さっき is used to modify a noun or a
noun-phrase. You could say e.g.「さっき書いたメール」 for "an e-mail [I] wrote just now"
though.

