The part of the sentence 'sat on the window' is correct and usable in written English.
You can use it to describe a situation where someone is sitting on the window sill. For example, "He sat on the window and watched the sun set over the horizon."
We were forced to sit on the window ledge out on the second floor because the one door out was blocked.
Sit on the window ledge and you can virtually tweak the top of the Empire State Building.
Elsewhere, Sienna Miller sits on the window ledge of dressing room number 9 at Theatre Royal Haymarket as she gets into character as Patricia in Flare Path and a serious-looking Keira Knightley, with rollers in her hair, prepares for The Children's Hour alongside Mad Men's Elisabeth Moss, who is also photographed.
The apartment's tenant, a net artist from the art collective Art404, sits on the window sill, smoking a cigarette and staring at the Empire State Building.
He looks momentarily like the man I would sit on the window sill waiting for; waiting for him to come in from work, worried there had been an accident at the factory, some 40 years previously.
Klaus sat on the bed closest to the window.
On his last day painting, he sat on the scaffold outside her window and watched her sleep; when she woke he asked her to act as if she were alone.
He sat on the sill of his open window, smoking behind a jungle screen of office plants.
I'll never forget the night I sat on the ledge of an upstairs window at The Edge, a gay bar in London's Soho Square, and told my friend Roland that my life was almost over.
In January, we sat on the squashy couch under our front window, legs tucked under a soft orange blanket from our former country house, and reaffirmed our commitment to split, at least on a trial basis.
