See above. I'm not sure what you mean by the speed at which they happen.Are all these sentences possible and similar in meaning?
1) The temperature has gone down to zero last night.
2) The temperature has fallen off to zero last night.
3) The temperature has dropped off to zero last night.
None of them are correct. The temperature went down to/fell to/dropped to zero last night.
If you remove "last night", then you can use the present perfect, but "fallen off" doesn't work at all, and we would use "has dropped" without the "off".
4) After CDs were introduced, sales of records went down sharply.
5) After CDs were introduced, sales of records fell off sharply.
6) After CDs were introduced, sales of records dropped off sharply.
7) The quality of his works has gone down as he has gotten older. as long as you mean "works" as in "books, records, paintings". Otherwise, it should be "work" if you are talking about how he does his job.
8) The quality of his works has fallen off as he has gotten older. Same as #7.
9) The quality of his works has dropped off as he has gotten older. Not natural.
I think they are all possible and what changes it the speed through which the action happens. Is this correct?
If I am not, could you explain why?
Thank you all.
- For Teachers