前置詞 because, since, as & so

FROM HAPA EIKAIWA

Because(cuz)：話し相手がこれから伝える内容を把握していない新しい情報を与える
I'm running almost everyday because I'm going to run a marathon.
I'm tired cuz I pulled an all-night last night. 徹夜した


since, as, so:相手がこれから伝える内容を把握、示唆できる情報を与える
Since it's raining, the baseball game got cancelled.
It's raining so the baseball game got cancelled.(soはカジュアルな表現）
He asked his boss if he could take the day off as he was feeling sick.
He was feeling sick so he asked his boss if he could take the day off.