linguistics / semiotics
or language / signs
Though the Greeks founded the European linguistic system, linguists around the 18th century realized the relationship between many languages that meant they must have come from a common source. This they called Proto-Indo-European, or PIE. Towards the end of the 19th century the structure of languages was studied, how they are put together and how they work.
Ferdinand de Saussure
Originally trained as a historical linguist, Saussure made important developments in the understanding of PIE. He says in his lecture on general linguistics "A linguistic sign is not a link between a thing and a name, but between a concept and a sound-pattern.[...] A sounds pattern i the hearer's psychological impression of a sound." He regarded language as a structured system whereas previous linguistic studies had taken an atomistic approach, seeing language as a collection of objects. Saussure approached synchronic linguistics, an analysis of the state of languages in general that applied to the existence of any language. He defined the linguistic sign into two parts, one the signifier and the other the signified. The former is technical / physical side of the sign, our vocal chords makes the vibrations that produce the sound or what we see as the written word. The signified goes hand in hand with this but is it he mental concept that follows the signifier. Thus these work together to form a bond.
Cognitive Linguistics
A different approach to the study of linguistics, it focuses on understanding the structure and function of language through human perception and recognition; the way we perceive the world partly determines the structure of our language and not the other way around, as was previously thought.
"To study language synchronically would be to study it as an entire system at a given point in time; to study language diachronically would be to study it and its development over a period of time."
Claude Lévi-Strauss