“On” is an overlooked preposition. It does so much linguistic housework for us, but we tend (if we are native speakers) just to watch it working as onlookers and take its work for granted, or (if we are language learners) to be infuriated by its seemingly arbitrary distribution compared to ‘at’ and ‘in.’

‘On’ is belittled from the outset by grammar books that present it in hackneyed ‘the book is on the table’ type phrases, suggesting that it is just about something resting passively on top of something else, depending lazily on gravity the way drug addicts depend on drugs. But, if my cat is ‘on television’, it means that my Facebook pictures of her have gone viral and she has appeared regularly in one of the more light-hearted segments of the Nine o’clock News. If she is ‘on the television’, on the other hand, she is just slumbering on top of an old-fashioned television apparatus, enjoying its warmth. Cats must hate flat-screen TVs.

Humble little housekeeper of a word that it is, ‘on’ still has a certain arrogance about it. It is always ‘on top of things’, ‘on to things’, ‘on the way somewhere’: a resourceful upwardly-mobile little word. “On’ always arrives ‘on time’, neither too early nor too late. It is always ‘on message’, always ‘on the job;’ it just goes ‘on and on’.