有一天

• in course of time
• one fine day
• one day
• someday
• sometime

例句

1. 不要老是把你的钢笔东放西放，否则总有一天会丢失的。
   Don't always leave your pen about or you will lose it one day.
2. 我们总有一天能聚在一起。
   Someday we'll be together.
3. 你那些恶作剧总有一天会使你自食其果。
   Your practical jokes will redound on you/your own head one day.
4. 她总有一天要出事。
   She'll have an accident one day.
5. 总有一天我俩都有机会看看纽约。
   One day we'll both get to see New York.