with一般有“和”的意思,如with sb.,但接sth.的时候意思应该看语境；
for一般有“为”的意思,可以表示目的,如为某人、为了什么事,这时候可以用for.
介词with和for的区别2：
For(介词)：关于,对于...来说,考虑到...的事实
-- The weather is quite warm for November.
-- For him,this will be an entirely new hobby.
With(介词)：在某一方面 (多用于二者的比较)
-- With some people,pleasure is more important than work.
-- Some people may accept that excuse,but it won‘t work with me.
