O

Hebrew

Can either make a long “o” sound (as in bone), or among some Ashkenazim it makes an “oy” (as in boy). The cholam can either appear as a dot at the upper left of a letter, or it takes the form of a vav with the dot above it.

Shoorook

Makes an “oo” sound (like boot) and appears like a vav with a dot to its left

Kubutz

Makes a shorter “oo” sound like in "book" and appears like three dots, arranged like an ascending staircase below the letter