The evolution of the script of any language must be based on symbols or signs denoting various "units" of its speech(phonemes). Most of the European languages including English are written in the Roman script. There is a script called Brahmi and the Asokan edicts are in it. In fact it is from Brahmi that the scripts of most Indian languages have evolved and these include not only the Devanagari script in which Sanskrit is written but also the Tamil and Grantha scripts.
The Brahmi lipi or script has two branches. Of the two, the Pallava Grantha script was prevalent in the South and it is from it that scripts of most of the Dravidian languages evolved.
The Telugu script has a unique feature. While in all other scripts the letters are written in a clockwise fashion, in Telugu there are letters written in an anticlockwise fashion, that is the loops are shaped leftward. Parasakti, the Supreme Goddess, is to the left of Isvara and there is leftist worship associated with her( "vama-marga"). For this reason it is believed that some of the letters of the Sricakra should be written in Telugu. The Andhra language itself is said to have a Saiva character. In most parts of India, the child is first taught to write the "Astaksari", [prayer to Vishu] but in Andhra Pradesh it is the "Siva Pancaksara". There are places sacred to Siva in three corners of this state: Kalahasti in the south, Srisailam in the west and Kotalingaksetram in the north. It is because this land is within the area marked by these lingas that it is called "Telungu-desa" (from "Trilinga"). Appayya Diksita has composed a stanza in which he expresses his regret that he was not born in Andhra.
Andhratvam Andhrabhasacapyandhradesa svajanmabhuh
Tatrapi Yajusi Sakha na 'lpasya tapasah phalam
Appayya Diksita was a Samadevin by birth. "Of the Vedas I am the Samaveda, "so says Bhagavan in the Gita. But Diksita, a great devotee of Siva, regrets that he was not born in Andhra, and that too as a Yajurvedin, and states that the reason for this was his failure to perform austerities in sufficient measure. The Yajurveda, it will be remembered, contains the Siva-Pancaksara mantra.
Let me revert to the question of script. As I said before, almost all the scripts in India today have evolved from Brahmi. But it is hard to make out elements of the original Brahmi in them. So anything that we find difficult to understand or make out is referred to as "Brahmi-lipi". Later this came into usage as "Brahma-lipi", the Creator's "writing" on our forehead [our destiny]. Now anything we find difficult to understand or cannot make out is called "Brahma-lipi". Another old script is "Kharosthi". "Khara-ostham" means the lips of a donkey - these resemble bellows. The loops protrude in the script. Persian is written in Kharosthi.
Brahmi was our common script just as Roman is today for most European languages. Now Devanagari [with variations] is the common script for most Northern languages. We do not realise that each letter or syllable represents a particular sound or phoneme. There are two different letters in Tamil to represent "na". Why should there be two to represent the same sound, we wonder, thinking it to be unique to that language. But there is a subtle difference between the two "na"s.
In Telugu there is only one "na". So is the case with other languages. There are two types of "r" common to Tamil and Telugu. But the two types differ in the two languages. In Tamil, two 'r's together of one of these two types form a consonant with a special sound value (kurram, marrum, sorannai). In Telugu it is different. The Tamil word for horse is "kudirai"; in Telugu it is "kurram" - the two r's are pronounced fully. In Tamil there is no such phoneme. There are some other unique phonemes in Telugu. In some words "ja" is pronounced as "za". Andhras pronounce "sala" as "tsala". The Devanagari and Grantha alphabets have 50 letters. In Telugu there are 52(including the additional letters in the "ja" and "ca" groups. The Telugu-speaking people sometimes interchange "tha" and "dha". I am told you find this in some of the compositions of Tyagaraja himself.
When we transliterate passages from one language into another we must keep these peculiarities in mind. In English also for the same labial there are two letters, "v" and "w". A professor told me that there is a difference between the two. The English "v" should be pronounced with the lower lip folded and the upper row of teeth coming into contact with it. When "w" is pronounced the lips do not come into contact with the teeth but are turned round. Words like "Sarasvati" and "Isvara" must be written with a "v" (not as "Saraswati" and "Iswara").
Sanskrit, more than any other language, exemplifies the principle of phonetic spelling. In English the spelling is erratic and confusing. I remember reading a newspaper heading recently: "Legislature wound up. " Absent-mindedly I read the word "wound" in the sense of a hurt or injury. Of course it was actually used as the past participle of "wind". Now the word "wind" can also mean a breeze but then it is pronounced differently. So it is all confusing. Is the word "put" pronounced in the same way as "cut" or "but"? In "walk" and "chalk", the "l" is silent.
Seemingly, such is not the case with Tamil which contains many words from other languages like Sanskrit. In other Indian languages for each series of consonants there are four different letters in place of the one in Tamil. For instance, the same "ka" is used for "kan" (Tamil for eye) and the Sanskrit "mukha" (in Tamil it is written as "mukham") while "Ganga" is written as "kanga" and "ghatam" (pot in Sanskrit) is written as "katam". In Tamil the word for mace ( the weapon wielded by Bhima) and for story are written alike as "katai", instead of as "gadai" and "kathai".
In Tamil, unlike in other Indian languages, "ka" serves the purpose of "kha", "ga", and "gha". "ta" serves for "da" also. Words that have almost opposite meanings are spelt identically: "Dosam" and "tosam" meaning blemish and happiness respectively are written identically. Letters from the Grantha script are added in Tamil for proper pronunciation _ "sa", "ha", "ja", "ksa", etc. In the past these letters were not used in Tamil poetry following the tradition of poetic usage. But now some authors do not use these Grantha characters even in prose. Since they find it difficult to get rid of Sanskrit words from the Tamil vocabulary, the next best thing they can do perhaps is to rid the language of the letters representing the phonemes of Sanskrit which have no equivalents in the Tamil alphabet. This causes confusion. If an author writes "catakam" in the strict Tamil manner it can read also as "sad(h)akam" or "jatakam". From the very beginning Tamil has not had all the consonants. But why should characters added to meet this deficiency be dropped? Does it mean "victory" for Tamil and "defeat" for Sanskrit? Why should there be a fight over languages? There is no need to nurse any bitterness against languages that we think are not our own.
The Tamil script is adequate to write words that are strictly Tamil. The difficulty is when it comes to its adopting words from other languages with sounds representing "kha", "ga", "gha", etc. In Sanskrit, Telugu, Kannada and so on, there are letters for the entire "ka-varga", "ca-varga", "ta-varga", "ta-varga", and "pa-varga". In English, as we have already seen, we cannot pronounce the words according to their spelling. It is not so in Tamil. But in that language too the script is not entirely self-sufficient. You may not agree. But I will tell you what I learned from my own experience.
A Northerner learned the Tamil alphabet sufficiently well, that is he learned to read the individual letters of the alphabet. But he had no one to help him in pronouncing the words properly. He wanted to learn Tamil because he was keen to read the Tevaram and the Tiruvacakam in the original. After learning the alphabet he tried to read the Tevaram from a book. Though he had no knowledge of the language he thought he could earn merit by reading the hymns of the great saints even without understanding their meaning. Then, one day, he came to me and announced: "I am going to recite the "Tevaram". " I felt happy and asked him to go ahead.
His recitation caused me amusement. The passage he had was a famous one - what Appar had sung at Tiruvaiyaru of his experience of seeing everything in the form of Umamahesvara [ that is the entire cosmos revealed as Siva ] and the song was "Madar piraikkanniyanai. . . " He got the very first word wrong. Instead of "madar" he said "matar". It sounded so strange to me. Then he said "malaiyan makalotu" for "malaiyan mahalodu" laying stress on the "k" and the "t". For "padi" he said "pati". I was on the verge of laughter. His recitation went on in this fashion. He said "pukuvar" instead of "puhuvar".
I heard him silently because I thought a Northerner learning a Tamil song deserved to be encouraged. But soon I found that I could no longer suffer his erratic reading. So I told him in a friendly manner that his pronunciation was faulty. To this he said: "What can I do? It is all in the book. " What he said was right and it showed that in Tamil too the words are not always written according to how they are pronounced. Letters that come in the middle of a word are not pronounced as they are written. We write "makalotu" but say "mahalodu"; we write "atarkaka" but say "adarkaha". "Ka" becomes "ha" in the middle and end of the word. "Ta" in the beginning of a word remains "ta" but in the middle becomes "da". For instance, "tantai" (father) is pronounced as "tandai" and "Katavul" (God) and "itam" (place) pronounced as "Kadavul" and "idam". Such matters are dealt with in detail in Tamil grammar books.
Like Sanskrit, Tamil too has excellent works on grammar - for example, the Tolkappiyam and Nannul. They deal with the morphology of words and their vocalisation. For instance there are such rules: After such and such a syllable "sa" becomes "ca", "ka" becomes "ha".
Generally speaking, if "ka" is the initial letter of a word in Tamil it retains its sound of "ka". In the same way if the initial letter of a word is "ta" it retains its true sound, but in the middle or end of a word it sounds "da". "Pa" is "pa" if it is the initial letter of a word but sounds "ba" in the middle of a word. (In Tamil we do not see "pa" occurring as an independent letter in the middle or end of a word. "Anpu"(love), "ampu"(arrow), "inpam"(pleasure) -"pa" in these words is joined with other letters. Words like "japa" (muttering the names of the Lord or any mantra); "sapam" (curse), "kapam" ("kapham", phlegm), "supam" ("subham", auspicious) have letters belonging to the "pa-varga" independently in the middle of the words but they are from the Sanskrit.
There is something interesting about "ca". While in Tamil "ka", "ta", "pa". etc, retain their true sound when they are the initial letters of words, "ca" as the initial letter is voiced as "sa". "Catti" (cooking vessel) and "civappu" (red) are pronounced as "satti" and "sivappu". But when the letters come together as "cca", they are not pronounced as "ssa"- for example, "accam" (fear), "paccai"(green). "Col" (to speak) is pronounced as "sol", but "peryarccol" and "vinaiccol" are not pronounced as "peyerssol" and "vinaissol". But in Malayalam which is derived from Tamil "ca" in the beginning of a word is pronounced as "ca": "civappu" is "civappu". But at other times when the "cca" comes in the middle of a word the word in pronounced as "ssa", not "cca", e. g, place names like "Kavisseri", "Nellisseri", while Tamils pronounce the same as "Kavicceri" and "Nellicceri". In words like "accan" (father) and "Ezhuttaccan", however, there is no change.
The genius of the Tamil language is to be known from its works on grammar- how a word is changed and where. However, the pronunciation is not in strict consonance with the spelling.
It is only in Sanskrit that the pronunciation is fully phonetic but for two exceptions. One is when there is a visarga before "pa". Visarga more or less has the same sound as "ha" - not a full "ha", though. In Tamil Nadu it is pronounced fully as "ha" and Northerners who slur over it are made fun of. But their pronunciation is correct according to the rules of Siksa. With the visarga occurring before it, "pa" becomes "fa".
The second exception: "Subrahmanya", "Brahma", "vahni"(fire) are pronounced as "Subramhanya", "Bramha" and "vanhi". But all words with "ha" coming as a conjunct consonant are not like this as, for example, "jahvara"(deep, inaccessible), "jihva"(tongue), "guhya"(secret), and "Prahlada" [son of the demon Hiranyakasipu and a great devotee of Visnu].
For a general background, please see here