applied linguistics cognitive linguistics comparative linguistics computational linguistics corpus linguistics descriptive linguistics etymology generative linguistics gradient well-formedness grammar historical linguistics history of linguistics language language acquisition language acquisition device language isolate lexical semantics linguistic anthropology linguistic prescription linguistics list of linguists list of unsolved problems machine translation nature versus nurture neurolinguistics origin of language phonetics phonology pragmatics pronoun prototype theory psycholinguistics psychological nativism second language acquisition semantics sociolinguistics statistical semantics structural semantics syntax tabula rasa theoretical linguistics translation undeciphered writing systems unsolved problems in chemistry unsolved problems in cognitive science unsolved problems in computer science unsolved problems in economics unsolved problems in mathematics unsolved problems in neuroscience unsolved problems in philosophy unsolved problems in physics unsolved problems in statistics