Compound letters

You can use the all the learnt vowels and and consonants to build the entire abugida.

Those letters that result from the combination of a vowel and a consonant are called a compound letters. In Tamil, there are 216 of them (12 vowels x 18 consonants).

You already learnt how to pronounce them when you learnt the consonants. Writing those letters isn't difficult either. Most of the times it is just about adding a diacritic or a helper character to the consonant.

And for all consonants, it will be the same helper character when combining a consonant with the same vowel.

So let's go column by column (so grouped by vowels) and learn the writing rules.

The அ-column

This column is the easiest one, once you know how to write the consonants. You might have noticed that every consonant has a dot on top of it. Like க்｢k｣, த்｢t｣, ப்｢p｣ or ம்｢m｣.

If you know leave out the dot on top of it, you already have the characters for the consonants combined with the short ｢a｣ sound:

க்｢k｣ + அ｢a｣ = க｢ka｣
த்｢t｣ + அ｢a｣ = த｢ta｣

The ஆ-column

If you want to write the characters that result from combining the consonants with the longer ஆ｢ā｣ sound, then you just need to add the helper ா character to the short version.

க｢ka｣ → கா｢kā｣
த｢ta｣ → தா｢tā｣

The இ-column

To write the letters of the இ｢i｣ column, you have to replace the dot with another diacritic: ி While the position of the diacritic is not always obvious (டி｢ṭi｣), the rule has no exception.

The ஈ-column

The longer version of the இ｢i｣ column, the ஈ｢ī｣ column follows the same rule as above, just with a different diacritic: ீ.

The உ-column

This column and its longer version are by far the more difficult ones. In theory they all follow a single rule, but the letters have been adapted to make them easier to write and therefore they sometimes look like they don't follow the rule.

The general rule for the compound letters of this column is just removing the dot and adding this diacritic ு. But in reality, that diacritic will be modified depending on the consonant.

There are different variations on how the letters are adapted and modified. The letter for :பு｢pu｣ is pretty simple. You take the ப்｢p｣, remove the dot to get ப｢pa｣, and then you add a small downwards pointing line and you get பு｢pu｣.

But there are other letters that extend the line and draw them around the character itself.

க்｢k｣ + உ｢u｣ = கு｢ku｣
ம்｢m｣ + உ｢u｣ = மு｢mu｣

The letter for ｢ṭu｣ even draws a longer circle.

ட்｢ṭ｣ + உ｢u｣ = டு｢ṭu｣

For this column it is the best to learn them by heart and practice them a lot. You will easily recognize them when reading though because all of them still look like their base consonant.

The ஊ-column

As for the shorter version, you will also have to learn the characters by heart for the long ஊ｢ū｣ vowel. The theoretical rule is to add a ூ but as for the short version the characters have been modified to make them easier to write.

The எ-column

For this column of compound letters, just remove the dot from the consonant and prefix it with the helper character ெ.

The ஏ-column

The longer version works the same, but with a different helper character. Prefix the consonant with a ே after removing the dot from it.

The ஐ-column

Combining a consonant with the ஐ｢ai｣ vowel is also done by removing the dot from the consonant and then adding a helper character in front of it: ை

The ஒ-column

The compund letters of the ஒ｢o｣ and the ஓ｢ō｣ vowels look similar to the combinations of the எ｢e｣ and ஏ｢ē｣ columns.

To build the compound letters of short ஒ｢o｣ vowel, you prefix the consonant with a ெ as you would do for the எ｢e｣ sound. But additionally you also add a helper character after the consonant: ா - The same helper character that you use for the ஆ｢ā｣ column.

The ஓ-column

For the long ஓ｢ō｣ you do the same. Prefix it with ே like you would do for the ஏ｢ē｣ column letters and suffix it with a ா.

The ஔ-column

The last column is for the ஔ｢au｣ vowels. They again look like the short எ｢e｣ using the ெ prefix, but for this column it is a different suffix: ௗ (Like for ஔ itself).