The song "Sing for the moment" by Eminem.
Idolize they favorite rappers and know all they songs
The song "Scars to your beautiful" by Alessia Cara.
She don't see her perfect, she don't understand she's worth it
So, my point is why are those forms used here and in many songs? I saw other words that are irregular. Is that only because they would sound nice in songs? Can we use them in everyday speech?