i have a problem in hard disk

hello all i have a problem in my mac os ..when i try to copy any file to my hard drive it give me this message "the item cannot be copied because there is not enough space"
i tried to add another hard disk and i formatted it ,it give me the same message .so what can i do

We're going to need a little more information. If you select your main hard drive (boot drive) and choose Get Info (Command I) in the Finder what are the numbers for al size and available space? Also what size file are you trying to copy?

Are either of the drives you are trying to copy to formatted Fat 32?

thanks man for your care and reply ........really i am new in ma c so i am sorry i am not understand much what you say but i want to tell you something is that the hard drive has more than 70 gega free and also i put another hard disk western digital 1 tera and i formatted it journaled mac.........the only place i can copy any file in the user profile only ................this is my first problem.......now i add new hard disk WD and it is required to install mac 10.5.8 on that hard disk first i install mac copy then by disk utility i restore this copy to the flash to make it bootable ...now when i begine to restart my apple pc and press and hold on option key to see the boot menu i see only the hard disk which have already mac installed......not see flash or the WD hard......is their any advice
....................i am sorry man for long
Thanks on advance