bowwow theory comparative linguistics derivation descriptive linguistics dialectology dingdong theory etymology glossematics glossography glossology glottochronology glottology grammar graphemics historical linguistics language study lexicography lexicostatistics lexigraphy linguistic geography linguistic science linguistics mathematical linguistics morphology morphophonemics onomasiology onomastics onomatology paleography philology phonetics phonology psycholinguistics semantics semasiology semiotic semiotics significs sociolinguistics structuralism syntactics transformational linguistics