For example, adding the suffix 'less' to the word 'care' to make 'careless' changes the original word’s meaning. Adding the suffix 'ful' to the word 'beauty' to make 'beautiful' changes the ...

COULD you please explain the meaning of the suffixes -less, -ful and -free and how to correctly use them? Why do priceless and useless have opposite connotations, one positive and the other negative?