What does 'language' actually mean when every day I see people mixing English and Spanish in the same sentence without noticing? I grew up in a bilingual home, and my parents insisted I keep both languages separate—English at school, Spanish at home. But my niece switches between them mid-thought, and she says it feels more natural than picking just one. Is that a loss of purity or just how living languages evolve? I honestly don't know if we're losing something or gaining flexibility, but I'd like to hear how others define the line between code-switching and proper language use.