Language is at the very core of connecting people to the society around them. Consider the young child who, for various intellectual or physical challenges, is functionally nonverbal. Without language, he is effectively cut off from the society around him with no means of expressing his basic needs, deepest desires, or greatest passions. Likely great measures will be taken to teach language skills to him in a way that he can both replicate and which will be understood in his social community. This connection to society is crucial in establishing a sense of identity and conveying the fundamental essence of one's beliefs, needs, and desires.
The ability to manipulate a particular language is also reflective of particular social groups one belongs to. Mastery of a standard or formal use of language can connect one to an identity of being well-educated. Mastery of the nuances of a particular dialect can connect a person to one's ancestry or to a particular culture. Mastery of expressive fluency in the concepts of a particular religion can connect one to a deep sense of spiritual fulfillment and to an identity and history belonging to a particular faith.
Through the ways a person is able to manipulate both the spoken and nonverbal aspects of language, she can be viewed as a great listener or an unwavering foe, as a compassionate ally or a tyrannical adversary, as a willing follower or a strong leader. These constant connections to others via language shapes one's identity in ever-changing ways as social contexts continually vary.