In spoken language, much of the meaning is determined by the context. That contrasts with written language in which more of the meaning is provided directly by the text. In spoken language, the truth of a proposition is determined by common-sense reference to experience, but in written language, a greater emphasis is placed on logical and coherent argument. Similarly, spoken language tends to convey subjective information, including the relationship between the speaker and the audience, whereas written language tends to convey objective information.
The relationship between spoken language and written language is complex. Within the field of linguistics the current consensus is that speech is an innate human capability, and written language is a cultural invention. However some linguists, such as those of the Prague school, argue that written and spoken language possess distinct qualities which would argue against written language being dependent on spoken language for its existence.
Both vocal and sign languages are composed of words. In vocal languages, words are made up from a limited set of vowels and consonants, and often tone. In sign languages, words are made up from a limited set of shapes, orientations, locations movements of the hands, and often facial expressions; in both cases, the building blocks are called phonemes. In both vocal and sign languages, words are grammatically and prosodically linked into phrases, clauses, and larger units of discourse.
Hearing children acquire as their first language the language that is used around them, whether vocal, cued (if they are sighted) signed. Deaf children can do the same with Cued Speech or sign language if either visual communication system is used around them. Vocal language are traditionally taught to them in the same way that written language must be taught to hearing children. (See oralism.)