competence (inglese) displacement (inglese) duality of structure (inglese) interchangeability (inglese) langue (francese) linguistics (inglese) productivity (inglese) typology of language (inglese) variety (inglese) artificial language (inglese) natural language (inglese) sign language (inglese) langauge pathology (inglese) communication (inglese) semiotics (inglese) zoƶsemiotics (inglese)