from now on,從現(xiàn)在起,一般用：“一般將來(lái)時(shí)；
from then on,從那時(shí)起,一般用：”一般過(guò)去時(shí).
I will study hard from now on.
I remebered her words from then on.
from...on 是英語(yǔ)習(xí)慣用語(yǔ),意思是“從所述的時(shí)間開(kāi)始而延續(xù)的時(shí)間未定”.一般都是做時(shí)間狀語(yǔ).
1.from now on 是從現(xiàn)在開(kāi)始,可以用一般現(xiàn)在時(shí),一般將來(lái)時(shí),
例：From now on you can work on your own.
From now on I will work harder and harder.
2.from then on是從那時(shí)開(kāi)始,一般指過(guò)去的某時(shí)間.可用一般過(guò)去時(shí),現(xiàn)在完成時(shí)（從那個(gè)時(shí)間點(diǎn)到現(xiàn)在）,
例:She never spoke to him from then on .
From then on I have got three toys from my father .