Tagalog was written in an abugida called Baybayin prior to the arrival of the Spaniards in the 16th century. This particular writing system was composed of symbols representing three vowels and 14 consonants. Belonging to the Brahmic family of scripts, it shares similarities with the Old Kawi script of Java and is believed to be descended from the script used by the Bugis in Sulawesi.
Although it enjoyed a relatively high level of literacy, the script gradually fell into disuse in favor of the Latin alphabet during Spanish colonial rule.
There has been confusion of how to use Baybayin. Each letter in the Latin Alphabet is not represented with one of those in the Baybayin alphabet. Rather than letters being put together to make sounds as in Western languages. Baybayin uses symbols to represent sounds.
A "kudlit" (resembles an apostrophe)is used above or below a symbol to change the vowel sound after its consonant. If the kudlit is used above, the vowel is an "E" or "I" sound. If the Kudlit is used below, the vowel is an "O" or "U" sound. A special kudlit was later added that resembles a plus sign, that is placed below the symbol to rid of the vowel sound all together, leaving a consonant.
Ba Be Bo B (in Baybayin)
Until the first half of the 20th century, Tagalog was widely written in a variety of ways based on Spanish orthography. When Tagalog became the national language, grammarian Lope K. Santos introduced a new alphabet consisting of 20 letters called ABAKADA in school grammar books called balarilà; A B K D E G H I L M N NG O P R S T U W Y.
As Pilipino, the national language, the alphabet was expanded in 1976 to include the letters C, CH, F, J, Q, RR, V, X, and Z in order to accommodate words of Spanish and English origin.
Filipino is the national language based on Tagalog that borrows vocabulary from other languages. In 1987, the Filipino alphabet was reduced from 33 to 28; A B C D E F G H I J K L M N Ñ Ng O P Q R S T U V W X Y Z.
Diacritics, or Palatuldikan, are normally not written in everyday usage, be it in publications or personal correspondence. The teaching of diacritics is inconsistent in Filipino schools and many Filipinos do not know how to use them. However, diacritics are normally used in dictionaries and in textbooks aimed at teaching the languages to foreigners.
There are three kinds of diacritics used in Tagalog:
Acute accent or pahilís
Used to indicate primary or secondary stress on a particular syllable. It is usually omitted on words that are stressed on the penultimate syllable; talagá.
Grave accent or paiwà
Placed only on the last syllable. It indicates that there is a glottal stop at the end of the word and that penultimate syllable receives stress; tadhanà.
Circumflex accent or pakupyâ
Placed only on the last syllable. It indicates that the final syllable of a word receives stress while there is a glottal stop that follows; sampû.