Ô

1. This letter most commonly makes the sound /oʊ/. It also suggests the stress of the word.

E.g.
hypnosis -> hipnôsiʃ
promotion -> promôcion
devotion -> devôcion
host -> hôst
post -> pôst
ghost -> gôst


2. Before the letters m and n, it is often pronounced /ɔr/:

E.g.
corn -> côn
storm -> stôm
to comform -> ta confôme


3. Before the letter v, it is pronounced /ər/:

E.g.
curve -> côve
hors d'oeuvre -> ordôve
to survive -> ta sôvîve

And sometimes in other words:
worm -> ɯôm


4. Where û would come after the letter ɯ, ô is used instead:
E.g.
woman -> ɯôman
wolf -> ɯôlf
would -> ɯoûd