Shell from Java with incised lines, sometimes claimed to be the oldest work of art
We do not know if they had language, but some anthropologists think their skulls show they could make a range of sounds as wide as ours. Recently genetic studies have suggested that the FOXP2 gene, which we know to be essential for language in us, probably evolved by a million years ago. So the early stirrings of our kind's astonishing invention probably took place among them. Since the bones of large animals have been found around their camps, they probably hunted in coordinated groups, and language would come in handy for that. After all they were not bigger or stronger than us, but on the contrary a little smaller and weaker, less able to strong-arm their way through life. Another advantage they may have had: studies of their shoulders suggest they were first species that could throw a spear with deadly effect.
They developed the way of life that defines us, using their big brains and clever hands to negotiate the world. They were smart and adaptable enough to survive through Ice Ages and hot times, across vast areas populated by beasts much larger and stronger than themselves.