介词 for 有这样一个含义:
because of or as a result of something
eg:
If, for any reason, you cannot attend, please inform us.
We could hardly see for the mist.
You'll feel better for a break.
介词 from 也有大致相同的一个含义,如下:
used to state the cause of something
mothers who are exhausted from all the sleepless nights
Death rates from accidents have been on the increase.
a patient suffering from stomach pains
The community benefits from having an excellent health service.