Since
例: She left school three years ago and has worked as a nurse ever since.
她三年前毕业, 从那时起便一直当护士。
(常用於现在完成式或过去完成式)自...以来, 从...至今
例: I haven't heard from him since last year.
我自去年以来未曾收到过他的信。
from
从...起, 始於
例: She is singing from morning to night.
她从早唱到晚
from now on
从现在开始
例: From now on, we will try to do better.
从现在开始我们要尽量做得更好。
from……on
since....
from...