how did talking even start, who invented talking?

[dan]

well they say when cavement were around all they did was grunt

but now in the modern day we have langue, english spansih french etc
but how did we even get to undetrstand as humans,

saying somting like "exspensive" to a cave man would be impossible to get him to understand because u can only use hand actions and show them

so how did it even happen lol