Many times, people end up giving up their parrots because the birds are unable to talk. In order to avoid later abandonment or turning the bird in to an animal shelter because it cannot be taught how to speak, one should consider the possibility that it may never talk.
There are some birds that simply never learn to do it. It greatly depends on the individual. They should not be sold or given up simply because they cannot learn the human language.
It appears that the commonly-spread little budgies/parakeets are some of the best talkers among parrots. Nonetheless, those budgies which are kept in pairs, or female budgies generally lack this ability.
The fact is, parrots love to communicate, and talking is just one way of transmitting feelings and information for them. Nonetheless, they can be taught. In order to succeed in the teaching process, try and associate words and phrases with pleasant moments, gestures, and events, to make it easier for the bird to associate what is said with what is done.
Since talking is about communicating things, a parrot can be taught to speak in a similar way that a kid is. Kids learn words that grown-ups say in relation to their momentary actions. They retain those words because they see their connection with things that are happening around them at that particular instance.
They can also relate words with emotions, for instance, when they are being kissed or hugged, in association with words like "I love you". So, the very best way to teach a parrot the same is to use the same words with the same activities repeatedly.
Birds, like most pets, learn to remember their very own name first. This is because they associate their names with their owners' calling them to feed them, of their coming home from work, or to their owners' petting them, giving them time, attention, affection, or playing with them.
So if you want to teach your parrot to talk, try and speak to it while giving it treats, cleaning its living space, or while walking into or exiting a room.
The idea is to associate each gesture or activity with a certain word or phrase. The bird will then start uttering those words anytime it sees you doing all those things for it, or perhaps when it wants something to be done.
It is not very difficult to teach your pet parrot to talk. However, simply getting it for the purpose of entertainment, and giving it up if it is unable to do so is cruel. Animals also have feelings and they do get affected. Thus, it is always better to know the reasons for wanting a pet before getting one, to avoid any such incidents in the future.