Question

it's years since和it's years before的区别

Answer 1

区别是：
it's years since指的是从那以来，表示已经几年了。
it's years before指的是几年前，表示在...之前已经几年了。

例句辨析：
it's years since
1、It's years since I've had a sore throat like I did last night.
我的喉咙已经好几年没有像昨晚那样疼了。
2、It's years since I last saw him, but he still looks the same.

几年没见，他还是那个样儿。
3、It's years since we parted.

暌违数载。
4、It's years since I came to this school.

我来这学校已经好几年了。

it's years before
1、Schwab warned last week in the United States that "if we can't get a breakthrough by January, February, March it's going to be several years before we get abreakthrough."
施瓦布上周在美警告说：“如果多哈谈判在今年没有取得任何突破性进展，恐怕就得等到几年之后了。”
2、Presence is moving closer to implementation, although it's still likely to be severalyears before it's widely used.

“定位”正在走近实际应用，虽然看起来其广泛应用尚须时日。
3、It was Rong Hong's plan that each receive 15 years of western education before returning to serve China.

容红的计划是让每个人接受十五年的西方教育以后，回中国效忠。
4、It's hard to make quick money through exporting, because it often takes years before you see any return on your investment.

做出口很难成为暴发户，因为你的投资需要好几年才能收回。

Answer 2

it's years since：从那以来，已经几年了。
it's years before：几年后，……。

举个例子吧：

It's years since my grandma died. 自多祖母去世后，以经有几年了。

It's years before I met her again. 几年后，我再次遇见了她。

Answer 3

It's years since we last talked 自从我们上一次谈话后,至今有好多年了吧

It's years before I heard from him很多年后,我才有他的消息.

1. It's + some time + since从句.
   翻译：“自从...以来已经多久了”.
   要求：since从句的时态必须是一般过去时.
   如：It's ten years since I graduated.
   自从我毕业以来,已经十年了.

2. It's + some time + before从句.
   翻译：“过了多久...才...”.
   要求：before从句的时态必须是一般过去时；It's = It was.
   如：It's ten years before I graduated.
   过了十年后,我才毕业.