The problem of split ends occurs when the cuticle is damaged and the fibres of the cortex unravel. This happens because of chemicals, neglect and harsh treatment.
Conditioner will not fix this problem. You will need to have the split ends cut off.
It is best to go to the hair dresser but you may do it yourself. Just take some small sections of hair strands, twist them, very carefully run some scissors up and down the hair shaft cutting off any stray ends that poke out.