The next vowel group you will learn is called the "O-type" because it indicates an "oh" sound (as in "roll" or "yellow") when combined with a letter. The O-type vowels can have the following vowel patterns:
Note that the "X" refers to any Hebrew letter (for example Aleph, Bet, and so on) and the rectangular box below the letter refers to a one the following types of vowel marks (nikkudim):
Although these vowel marks look different, they all represent an "oh"sound.
By far the most common of these vowels is Cholem and Cholem Vav (i.e., Chateph Qamets appears only under the guttural letters and Qamets Chatuph is somewhat rare).
Note that both Cholem and Cholem Vav are long vowels (Cholem is actually a "defective spelling" of Cholem Vav), Chateph Qamets is a reduced vowel (i.e., a "half vowel" that can only appear under the guttural letters), and Qamets Chatuph is a short vowel.
The "Qamets Chatuph" is an O-Type vowel that looks identical to the regular A-Type Qamets vowel. When you see a Qamets, you must ask 1) is it in a closed syllable? (i.e., a syllable that ends in a stopping sound) and 2) is the syllable unaccented? (most Hebrew words are accented on the last syllable). If both conditions are met, the Qamets is Chatuph and should be pronounced as an "o" sound.
A syllable is called "open" when it does not end with a "stopping" sound:
A syllable is called "closed" when it ends with a "stopping" sound: