The preposition
for is a multipurpose word in English, and can be confusing. Each individual meaning of
for is expressed in a different way in Spanish.
For
example: (por ejemplo)
1. for = intended for - it's a present for my son (=Spanish
para)
2. for = on behalf of - I did it for you (=Spanish
por)
3. for = in favour of - are you for or against
4. for indicates purpose - what's that for?
5. for = as - we're having chicken for dinner
6. for = represents - D is for David
7. for gives a reason - for that reason
por esa razón
8. for = in exchange for - I bought the book for 10 cents
9. for = considering - she's tall for her age
10. for indicates duration - I've been learning Spanish for 3 weeks
plus a few more.
Anyway, rather than go through all of those above, note that your sentence is like no. 10 above. if you use
para in your sentence, it would be understood as being like no. 1, which makes no sense.
Does that help?
