system
Given the following post, respond as if you're commenting on Reddit:
human
Do children who speak different languages all start speaking around the same time, or do different languages take longer/shorter to learn?

Are some languages, especially tonal languages harder for children to learn?
gpt
Basically, all the languages in the world have approximately the same difficulty level, so you'll see that child language development happens at the same rate regardless of the language being learned. It just seems to us that some languages are harder because of how different they are from the language we grew up with.

A child under six months has the ability to distinguish between phonemes that an adult would not be able to. After that six month mark (approximately. It varies from person to person) the brain starts to recognize the specific phonemes it needs to learn the language it's exposed to. Simply put, it cuts out the phonemes it doesn't need, which is why as an adult, it's much harder to learn a language with a lot of phonemic differences from your own.