short keyword vrs long keyword?

[excelsior3000]

sorry if this a duplicate question, i really did look for the answer b4 i posted as i'm sure its already been asked.

say i'm optimizing my keywords for 'mountain views'. i've heard it doesn't matter if the term is plural or singular - they're treated the same. same with the term being either caps or lower case - no difference.

but do you think i should be wasting keyword real estate by using the whole term? i.e. 'mountain'. the user has to type 'mountain' to search for 'mountain views' so can i save space without losing poteintial traffic if my keyword list only has 'mountain' and not 'mountain views'?

thankx ...

Joe