Not only does it help you express yourself, it essentially helps you think. If you lack language to describe something, be it a feeling, and object or anything else, its very hard to grasp the concept of it, let alone explain it to someone else. Sure, you could use common words, but you’ll be limited to what they represent in your thought process. For example, I might feel sadness—but maybe I actually feel grief, or melancholy, or longing, or yearning, or heartache (and so on). Most words aren’t exact synonyms; they represent shades of meaning you might want to convey or understand. Language even affects how you think about distinctions between things. Are light blue and blue shades or different colours, for example? Depends on what you call them in your native language.

Lacking language makes defining your identity harder, too. Sometimes people deliberately try to deny someone else the words to describe what is happening to them and/or what they are, and it’s a powerful tool that fucks you up.