^ Cute as having a talking pet may be, it isn't a good reason to get a bird, and many people sadly do get it just for the novelty of a chatting pet. Unfornuately, it also leads to many of them being surrendered, when they pick up unfavorable words, other pets' noises, telephone rings, etc. and repeat them loudly and often, to the point of the owner's annoyance. Learning to mimic things like a loud door bell or a curse word then makes these birds very hard to place.
That said, your love bird may be able to talk, but they aren't really known for it, so its vocabulary will probably be quite limited. Maybe about on par with parakeets, which can talk, but take a very long time to train vocabulary into, and are capable of a only a fairly limited range of words. That, and love birds prefer other birds much over people, so if they have another lovebird, they'd probably be inclined to just chat with him/her instead.
As someone allready said, repetition is the key. It couldn't hurt to reward the animal when it does speak, as well. Be careful not to repeat things you DON'T want it saying; once it figures out that talking pleases you, it might start learning to repeat other things. If you listed to death metal or rap every day, it might just pick up some nasty language.
My parrots only say a few things, and things they learned just from me saying it, not from training. My amazon parrot says his name (Pretty Bird... I'd love to shoot his former owners for that gem), and mimics a variety of whistles. My other parrot, a conure, says "Kiss you," "Hop up," "Aspen" and "Be nice." He also makes a lot of incoherent babbling that sounds like attempts at human speech, but with no real words being said. And my eldest parakeet, Velveeta, has apparently learned Pretty'd Bird's name, and spouts off long, annoying streams of "Pretty pretty pretty preeeeeetty prrrrrrretty pretty bird bird prettttty." Our former parakeet (many years ago) had a pretty expansive vocabulary, though I don't remember much of it.