Okay kiddo, have you ever seen a bird speak like a human? Some birds, like parrots and mynahs, can actually learn to mimic human speech. It's kind of like how you learn to say words by listening to your parents and teachers.
When a bird hears a person talking, it tries to copy the sounds it hears. It uses its syrinx (that's what birds call their voice box) to create different sounds, just like we use our vocal cords. With practice, some birds can learn to say lots of words and phrases!
But don't be fooled, these birds don't really understand what they're saying. They're just repeating sounds that they've memorized. They might think they're saying something like "hello", but they don't actually understand the meaning behind the word.
Also, not all birds can talk. It's mostly just parrots, mynahs, and some other types of birds that have the ability to learn human speech. So if you see a bird in your backyard, don't expect it to suddenly start talking to you!