While most consonants sound distinct, there are subtle differences in the pronunciation of the consonants ‘ங்’, ‘ஞ்’, ‘ண்’, ‘ந்’ and ‘ன்’, the pronunciation of the consonants ‘ல்’, ‘ள்’ and ‘ழ்’ and the pronunciation of the consonants ‘ர்’ and ‘ற்.’ The difference in pronunciation usually depends on the position of the tongue against the upper-palate of the mouth.
‘ன்’, ‘ண்’, ‘ங்’, ‘ஞ்’, and ‘ந்’
ன் is called ‘rendu soolli navana’ (the letter N with two circles). When you pronounce it, the tip of your tongue should lightly hit your teeth. It never occurs at the beginning of a word.
‘ந்’ sounds similar to ன். It often appears next to ‘த’ in a ‘ந்த’ pair and has a slight ‘th’ sound. For example: அந்த (that), மந்திரி (minister), கந்தோர் (office), பந்து (ball). As a consonant (ந்) it can occur in the middle of the word, otherwise it occurs at the beginning of a word. It never occurs at the end of a word, except in names.
‘ண்’ is called ‘mundu soolli navana’ (the letter N with three circles). When you pronounce it, the tip of your tongue should roll back and hit the back of your hard palate or the roof of your mouth. It never occurs at the beginning of a word.
‘ங்’ often appears next to ‘க’ as the ‘ங்க’ pair and has a slight ‘g’ sound at the end. For example: வங்கி (bank), பூங்கா (park), இறங்கு (climb down).
‘ஞ்’ has a slight ‘j’ sound at the end.
‘ல்’, ‘ள்’ and ‘ழ்’
‘ல்’ is called ‘small L’ or ‘pambu lana’ (the snake like letter L). When you pronounce it, the tip of your tongue should hit your teeth.
‘ள்’ is pronounced by the tip of your tongue hitting the middle of your hard palate.
‘ழ்’ is called ‘big L’. When you pronounce it, the tip of your tongue should roll back and hit the back of your hard palate. When transliterated in English it is written ‘zh.’
‘ர்’ and ‘ற்’
‘ர்’ is called ‘small R’ or ‘soft R.’ When you pronounce it, the tip of your tongue should lightly hit your front teeth.
‘ற்’ is called ‘big R’ or ‘hard R’. When you pronounce it, the tip of your tongue also hits your front teeth but harder, but it has a slight ‘t’ sound too. The consonant ற் never begins a word.