1. early: if something happens early, it happens before the usual time or the most suitable time; if someone is early, they arrive before the time they are expected to

例：

I finished work early today. （我今天提早收工。）

After an early lunch, we started the meeting at one o'clock. （我们提早吃过午饭，1点开始开会。）

be early (for something) (=arrive early)

You're early—I wasn't expecting you till seven. （你来得好早，我本以为你7点才会到。）

I'm sorry; I'm a bit early for my appointment. （抱歉，我来得有点早了。）

seven months/three days etc. early (=seven months/three days etc. earlier than expected)

Our first child was born eight weeks early. （我们第一个孩子早产8周（即比预产期提前8周出生）。）

2. ahead of time: earlier than the time when you have arranged or expect to do something

例：

We will try to complete the building ahead of time. （我们尽量提前完工。）

You can always prepare the salad ahead of time and refrigerate it. （你可以提前做好沙拉，放在冰箱里。）

He called the restaurant ahead of time to make a dinner reservation. （他提早给餐厅打了电话，预定好了午餐的座位。）

She read the report ahead of time to prepare for the meeting. （她提前看了报告，为会议做好了准备。）

Prepare what you plan to say in the meeting ahead of time. （提前准备好你在会上的发言。）

''ahead of time''的反义词：''behind time''。

例：

The train left twenty minutes behind time. （火车延误了20分钟。）

3. ahead of schedule: earlier than the officially agreed time

例：

The builders were ahead of schedule. （建筑工人提前完工。）

Due to the economy's strong recovery, Mexico will repay ahead of schedule the last installment of a $13.5 billion loan. （墨西哥经济强劲复苏，将会提前还完135亿美元贷款的最后一期。）

six months/two weeks/a year etc. ahead of schedule

The renovation of the school has just been completed three months ahead of schedule. （校舍翻新提前3个月完成。）

4. in good time: early enough, so that you do not have to rush, or so that you have time to get ready

例：

I like to get all my Christmas presents bought and sent in good time. （我喜欢提前买好圣诞礼物，早早寄出去。）

It is important to arrive in good time for your interview. （面试时早点到很重要。）

5. with time to spare: if you arrive somewhere or finish something with time to spare, you arrive or finish before the time when you have to arrive or finish

例：

In spite of the bad traffic, we reached London with plenty of time to spare. （尽管交通拥堵，我们到伦敦时，还是比预定时间提前了很多。）

He got there with time to spare. （他到那儿时，比预定时间提早了很多。）

with ten minutes/half an hour etc. to spare

I finished the test with just two minutes to spare (=two minutes before the end). （交卷前两分钟，我才把考卷做完。）

He got there with minutes to spare. （他刚好赶得及到那儿。）

We have very little time to spare. （我们快来不及了。）

补充：''with ... to spare''还可以跟''money''，''energy''等搭配使用。

例：

He seems to have energy to spare. (=He seems to have a lot of energy.)（他好像有使不完的力气。）

I have no money to spare (=do not have enough money) for such things. （我没钱买这些东西。）