Speech sounds cannot be understood, delimited, classified and explained except in the light of the tasks which they perform in language.
Roman JakobsonA new era in the physiological investigation of linguistic sounds was opened up by X-ray photography.
Roman JakobsonLanguages differ essentially in what they must convey and not in what they may convey.
Roman JakobsonSemantics, or the study of meaning, remained undeveloped, while phonetics made rapid progress and even came to occupy the central place in the scientific study of language.
Roman Jakobson