ahead
单词辨析：
指在时间上先于另一事发生或完成，尤用于谈论准备或计划的事情。
If you have completed most of the homework beforehand, you'll enjoy the evening more.
如果你预先把大部分家庭作业做完了，这个晚上你会玩得更开心。
Please inform us of your arrival time beforehand.
请事先通知我们你抵达的时间。
Saunas can be dangerous if misused. Avoid a big meal beforehand.
洗桑拿浴如果方法不当会有危险，浴前切忌饱食。
How could you tell beforehand that I was going to buy a Ford?
你怎么会事先知道我要买一辆福特轿车？
词义同 beforehand，常可换用；但以 ahead of time/schedule 出现时，则其中的 ahead 不可与 beforehand 换用。
Do book ahead/beforehand as the hotel is very popular.
该酒店非常受欢迎，请务必提前预订。
Winter weddings need to be arranged months ahead/beforehand.
在冬季举行婚礼需要提前几个月作安排。
If you had warned me ahead of time, I wouldn't have done that.
如果你预先警告我，我就不会那样做了。
The train left 3 minutes ahead of schedule.
火车提前3分钟离站了。
相关例句：
Henry generally stayed ahead of the others in the academic subjects.
亨利的文化课成绩通常都优于其他学生。
Now I can remember without mourning, and begin to look ahead
如今回首往事我已不再感到悲痛，并且开始展望将来。
A goal would have put Dublin 6-1 ahead.
只要再进一球，都柏林队将以6比1领先。
The government wants figures that help it to plan ahead
政府需要一些有助于其提前制订计划的数据。
She spent all night thinking about the future that lay ahead of her
她整夜未睡，满脑子都想着她未来的前途。
I tried to think about all the problems that were ahead of me tomorrow
我试图考虑明天我将面临的所有问题。