"there on purpose" is correct and usable in written English.
You can use this phrase to indicate that someone or something is in a particular place intentionally, for a specific reason. For example: "The cat was there on purpose; it knew there was a bowl of milk waiting for it."
Surely no one would leave it there on purpose.
The porridge itself, too, contained more lumps, hairs and unexplained black things than one would have thought possible, unless someone were putting them there on purpose".
My soggy tuna fish sandwich was manna compared with his porridge, which contained "more lumps, hairs and unexplained black things than one would have thought possible, unless someone were putting them there on purpose".
It was almost like they were planted there on purpose".
How does she know he left it there on purpose?
We had crawled in there on purpose to explore each other.
There are no experts featured on the show -- on purpose.
That's bad brickwork over there, done on purpose.
The action is set on an Arctic research facility that has accidentally – or, judging by some of the plainly sneaky people working there, accidentally on purpose – unleashed a catastrophic virus that threatens all of mankind.
They were constructing an edifice of their own, as striking, in its way, as the station: a fortress of plastic milk crates, ten crates high, stretching farther than the eye could see, packed with broken amphorae, horse bones, anchors, ceramic lamps, hewn limestone, mining refuse — anything that had been left there, accidentally or on purpose, by human hands.
Yet what distinguishes one from another should be their "why". So, there's an increasing importance on purpose because there are a lot of people, particularly Millennials, who are making employment decisions not based on profit potential, or even salary potential, and earnings potential, but on purpose alignment.
