I am not a teacher.
Wow. The Macmillan "dictionary" is wrong. It's "out the window". "Out of the window" is a mistake made by people who haven't read very much, but I will admit that it's a quite frequent mistake. The Macmillan so-called dictionary is a descriptivist dictionary, which means that it describes what people say rather than recognizing standards of correctness. If you want to speak and write in a colloquial register, use it. If you want to sound literate, do not.
"I had seen Uriah Heep's pale face
looking out of the window."
David Copperfield, Dickens.
" ... or the chief of the time between breakfast and dinner was now passed by him either at work in the garden or in reading and writing, and l
ooking out of the window in his own book-room, which fronted the road."
Pride and Prejudice, Jane Austen.
"Do what he might, in any case, his previous virtue was still there, and it seemed fairly to
stare at him
out of the windows of shops that were not as the shops of Woollett" The
Ambassadors, Henry James.
"Celia observed that Dorothea, instead of settling down with her usual diligent interest to some occupation, simply leaned her elbow on an open book and
looked out of the window at the great cedar silvered with the damp.
Middlemarch, George Elliot.
"He bled her, and he told me to let her live on whey and water-gruel, and take care she did not throw herself downstairs or
out of the window"
Wuthering Heights, Emily Bronte.
"She left her bed and
looked out of the window."
Far from the Madding Crowd, William Hardy.
"You speak in riddles, learned sir," said the pale minister,
glancing aside out of the window"
The Scarlet Letter, Nathaniel Hawthorne
"Even as it was, I thought something of slipping
out of the window..."
Moby Dick, Hermann Melville.
=====================================================================================================
I'm always willing to learn, Coolfootluke, and I wouldn't want to appear illiterate. What books should I be reading?