from
from to是完成时吗？
to是完成时吗？
from to 是指整段时间, 可用完成时如 this shop is opened between 2 and3 (2到3见开门) this shop has opened from 1to2(一到两点的都营业)。
then是什么时态的标志？
then的意思是那时 ,相当于at that time，那时就说的是现在之前的某个时间，所以一般用过去时，比如说那个时候我们彼此关系特别好，We were on good terms then，但是如果说成since then，自从那个时候起，那么就用现在完成时，如果用说from then on，从那时起我们就一般过去式。
from now on什么时态？
From now on，意思是,从现在开始。后面既可以接将来时,也可以接一般现在时。
From now on, I will work harder than before.本句话就用的将来时。
From now on,I hope men also share more household chores raising our children.#34这句话用的是一般现在时。
希望我的回答对你有所帮助！
from the on用什么时态？
你写错了，应该是from then on意思是从那时起，应该是用一般过去式！I joined the PLA then on,I began to teach my self English，I have taught myself for over two that I left the ARMY. I became a middle school teacher . I taught students English .
from与since表时间有什么区别？
1)from：从……起(时间)
表示从……开始时，一般都是用词组from…to…，而单纯表示确切的从几点开始时用at。
The meeting will be held from eight to ten.
这个会议将从8点开到10点。
The meeting will be held at eight.会议将从八点钟开始。
比较:
since和from since表示时间时，一般只用于完成时的句子;而from也用于现在时、过去时及将来时态。
另外since还可以作连词(见下例);而from则不可以，它只能作介词。
2)since：自从……以来(表示从以前某时一直到现在仍在继续)
I have been sick since yesterday.
我从昨天就病了。(一直到现在)
The doctor has saved a lot of lives since he became a doctor.(since作连词)
这个医生自当医生以来已经拯救了许多人的生命。