Baybayin is an abugida writing system consisting of 14 consonants and 3 vowels. Each of the 14 consonants ends with the vowel “A”.  For example, the letter B would be BA. The Thai, Balinese, and Sanskrit scripts also have similar characteristics.

The original “alphabet” consists of the following characters:

Vowels
A | E | I | O | U

Consonants
Ba | Ka | Da | Ga | Ha | La | Ma | Na | Nga | Pa | Sa | Ta | Wa | Ya

Kudlit
The kudlit is a small mark above or below a consonant character to change the pronouncing properties.
The KA character alone looks like this:

With the kudlit above it would be either KE or KI.

A kudlit below the character would be either KO or KU.