1.含义不同
long before 意为“在很久之前,很久以前”
before long = soon 意为“不久之后”
例句1:Long before I knew better.
很久以前我就知道了。
例句2:Before long, Zoe is ready to roll!
不久之后,Zoe就准备好了!
2.用法不同
long before体现过去时态,常用于过去时或过去完成时。
before long用作时间状语,常与将来时、过去时态连用。
例句1:She had left long before. 她老早就离开了。(过去完成时)
例句2:I'll be back before long. 不久我就回来。(一般将来时)
例句3:Before long he got married. 不久他就结婚了。(一般过去时)
before long
1、Before long she had been called upon to undertake another journey.
不久以后,她将被号召做另一次旅行。
2、Before long you will notice the changes in your life, as that which you ask for manifests.
不久以后,你会注意到你生活中的变化,就像你请求所显现的那样。
3、We'll be home before long.
我们很快就要到家了。
long before
1、We have heard about this new type of machine long before.
关于这类新型机器,我们很久以前就听说过。
2、The reference book for teaching came out long before.
教学参考书很久以前就出版了。
3、The area was inhabited long before the dawn of recorded history.
早在有历史记载之前很久这个地区就有人居住了。