Use of expression "out of"
Solution 1:
The normal thing is "out of", especially in BrE, as in
1 He looked out of the window.
AmE tends to shorten "out of" sometimes to "out" as in
2 He looked out the window.
The normal thing is "out of", especially in BrE, as in
1 He looked out of the window.
AmE tends to shorten "out of" sometimes to "out" as in
2 He looked out the window.