Please reply at your earliest convenience.

请尽早回复。

He died suddenly in his early 50s.

他刚50出头就突然去世了。

The early bird catches the worm.

早起的鸟儿有虫吃。/先下手为强。

Early to bed and early to rise makes a man healthy, wealthy and wise.

睡得早，起得早，富裕、聪明、身体好。

The next day, we set off early in the morning.

第二天，我们一大早就出发了。