[unitedhumanists.com]

It's likely that other species of humans had language too (Neanderthals and Denisovans in particular, but all three species [ours, Neanderthals and Denisovans] likely inherited language from homo erectus). The modern humans that spread out of Africa would certainly have had language already and not developed it independently in many places later on, and it's also likely that they're all natural languages are still related (without any of them ever being constructed completely from scratch, even if a pidgin phase was involved). I doubt any Neanderthal or Denisovan language spread into the languages of modern humans - the DNA that got into us from them (2% Neanderthal or Denisovan DNA in most non-Africans, and 4% Denisovan DNA in Aborigines) was most likely not the result of loving relationships.