The long-running series in which readers answer other readers’ questions on subjects ranging from trivial flights of fancy to profound scientific and philosophical concepts
Why is a child going “Na-na, na-na-na!” annoying the world over? I read recently that kids do a version of this in every culture and country. Fred Corbett, London
Post your answers (and new questions) below or send them to nq@theguardian.com. A selection will be published next Sunday.