Lean can be either transitive or intransitive.Originally Posted by 1044070
You can lean against/on a wall or lean on somebody. This means that your body is resting against a wall or another person in an inclined position.
You can also lean something against/on a wall. e.g. I leaned a ladder against the wall. This means that you rested the upper end of the ladder on the wall.
Hope this helps.