Kakariki aren't known for their talking abilities but then again neither are cockatiels and ours talks A LOT! It won't be as definied or clear as a parrot like an indian ring neck, african grey or a macaw. However, Kakarikis can sing beautifully. Its all about enriching them through training, playing and talking to them. Eventually they may imitate or pick it up but some don't, it can take over a year before you hear a single word if at all. It took our previous cockatiel 5 years before he uttered anything like a word so its all a patience thing but accepting the fact that it mgiht not happen and enjoying the bird's personality. Kakarikis have such wonderful and expressive personalities when you nuture them

Good Luck