Is there any sufix which gives the opposite of the word other than -less,i.e care-careless.
It's the only one I know.
http://grammar.about.com/od/words/a/comsuffixes.htm
Yes, there are several suffixes that can give the opposite meaning of a word. One such suffix is "-ful." When added to a word, "-ful" means "full of" or "characterized by." However, it can also be used to create the opposite meaning of a word when paired with a negative prefix. For example:
1. Careful - Full of care, cautious
Careless - Without care, not cautious
2. Joyful - Full of joy, happy
Joyless - Without joy, unhappy
3. Faithful - Full of faith, loyal
Faithless - Without faith, disloyal
So, when looking for a word with the opposite meaning, you can consider using the "-ful" suffix, either by applying it directly to the word or by combining it with a negative prefix such as "un-" or "dis-".