on the floor, on the ground on page eleven on the second floor on the list, on the menu on a bus, on a train, on a plane, on a ship
AT
at the top of/at the bottom of (a page) at the front of/at the back of (a building, theatre, group of people) at (on) the corner of (a street, square etc.) at sea, at the seaside at a conference, at a party, at the meeting etc.
IN
in the corner of (a room, a kitchen etc.) in a row, in a line, in a queue, in a street in the mountains, in the world, in the sky, in the sun in hospital, in prison, in bed in London, in Europe
