Possible Clues:

• Linguist's concern
• Branch of linguistics
• Appear half-hearted, with silly behaviour in linguistic inquiry
• Meaningful study
• The significance of a text means it's wrenched out of chapter
• Main sects (anag.)
• Meaning to study here in house I abandoned fooling about
• Calls back, and nervous reactions result in different interpretations of language used
• Meaningful study of London area mayhem's beginning with foolish behaviour
• The meaning of words initially shifting? This setter's flipping tricks!