system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How did the the first language start, or at least how we think it started?
gpt
It probably started from sounds that we made naturally - we scream when we are scared or hurt, we laugh when we are happy, we grunt when we want someone's attention.  We recognize those sounds instinctually and just innately know what they mean.

From there, it wouldn't have taken our hunter/gather ancestors too much effort to figure out that hunting was easier if Grog responded to a low grunt and Krik responded to a high grunt only - it would allow you to only get the attention of the person you were after.

From there, it wouldn't take much effort to have a different kind of grunt to signify that you saw prey, perhaps even specific enough to tell them what type of prey they were hunting.

Keep iterating this logic and, bam, you have language.