What are ways to express...?
Good morning in Japanese
I know that ohayo gozaimasu is good morning in Japanese, but I hear people using different things depending on who they're talking to.
What are the other ways people say it, and why/when do they use them?
Men to other men they know and are on the same level with (same age, etc.), generally just give a hearty "oos" sound (the oo is like the 'u' in 'put').
That just comes from shortening the word ohayo gozaimasu to the oh at the beginning and the s sounds at the end.