one day，some day用法及区别

one day作“某日”解时，容易和some day混淆。

one day既可指过去的某一日，也能指将来的某一天。用以指过去的场合比用以指将来的场合要多得多。例：

I met my primary schoolmate one day last week.

上星期，有一日我遇到一位小学同学。One day when I was on the beach，I came across a strange incident.

有一日，在沙滩上我碰到一件怪事。

We hope to see you again one day.

我们希望将来有一天能再见你。

some day只能用以指将来，不可以指过去。例如，我们可以说I hope to see him again some day但不能说I saw him some day。例：

If you don't change，you will be sorry for it some day.

如果你不改变，将来有一天你会为此而感到遗憾的。

I will tell you of the event some day.

将来有一天，我会把此事告诉你的。