Expressing "ever since" with "yilai"
You can express "ever since" in Chinese using 以来 (yǐlái) with a time in the past. Just the word 来 (lái) can also play a similar role.
Pattern with 以来
To express "ever since," all one needs to do is put 以来 after a specific event or time. It expresses what has happened since the stated event until the time that the speaker talks (in other words, referring to a certain continuous time period leading up to the present).
This grammar pattern is usually used to start a statement.
Time / Event + 以来 ，⋯⋯
Although we won't go into detail here, note that when using 以来 in a more formal or written context, you can add 自, 从, or 自从 (or other similar words) before the time or event to make it into a "sandwich pattern."
- 今年 八月 以来 ，这里 一直 没 下 过 雨 。It hasn't rained since August.
- 结婚 以来 ，我们 没 吵 过 架 。We've never had a fight since we got married.
- 上 大学 以来 ，他 变 了 很多 。We've never had a fight since we got married.
- 从 我 八岁 以来 ，我 就 没有 见 过 他 。He hasn't returned home since his father passed away.
- 从 我 学 汉语 以来 ，我 认识 了 很多 中国 朋友 。He hasn't returned home since his father passed away.
Pattern with 来
Using 来 to mean "ever since" is basically the same as 以来. However, there is one key difference: you can only use 来 after a length of time, rather than a specific date. In other words, it needs to be used with a certain number of years, months, days, hours, etc. In English, this would be like saying "Ever since three days ago, I've had a constant headache." It doesn't have to be a specific number either; it could be "a few" (几).
Time Period + 来 ，⋯⋯
This form cannot be used with 自, 从, or 自从 (or other similar words).
- 十 年 来，房价 一直 在 涨 。In the past decade, housing prices have been going up.
- 几 年 来 ，我们 公司 的 收入 一直 在 增加 。Our company's income has been increasing over the past few years.
- 实习 几 个 月来 ，我 学到 了 很 多 。I've learnt a lot from my internship during the last few months.
- 出国 几 个 月 来 ，她 一点 也 不 想 家 。She hasn't missed home at all since she went abroad a few month ago.
- 离婚 这 几 年 来 ，他 从 没 去 看 过 孩子 。He hasn't visited his child since he got divorced a few years ago.
- 这 三 个 月 来 ，我 每天 都 在 想 她。She hasn't missed home at all since she went abroad a few month ago.