Humans seem to have much higher degrees of consciousness and agency than other animals, and this may have emerged from our capacities for language. Helen Keller (who was deaf and blind since infancy, and only started learning language when she was 6) gave an autobiographical account of how she was driven by blind impetuses until she learned the meanings of the words βIβ and βmeβ
Possible nitpick depending on how you define consciousness: this excerpt sounds like Keller was conscious in the global workspace sense, but rather lacked something like a phenomenal self-model.