Tamil Sandhi Rules — புணர்ச்சி விதிகள்
Sandhi (punarchi) rules govern how Tamil words join together. Master these 5 rule types and eliminate the most common errors in formal Tamil writing.
What is Sandhi in Tamil?
Sandhi (புணர்ச்சி, pronounced punarchi) is the set of phonological rules that govern how Tamil words combine at their boundaries. When two words are placed next to each other, the sounds at the junction often change — letters are added, dropped, or transformed.
These changes follow strict rules codified in classical Tamil grammar (தொல்காப்பியம்). Sandhi errors are the #1 mistake in formal Tamil writing because the spoken form sounds natural even when the written form is wrong — making them hard to self-detect.
5 Key Sandhi Rule Types
Glide Insertion — யகர (Y-glide)
When a word ending in ஐ, ஏ, or ஒய் is followed by a vowel, the glide consonant ய் is inserted.
Before
கை + அடி
After
கையடி
Phonetic
kai + adi → kaiyadi
Glide Insertion — வகர (V-glide)
When a word ending in ஆ, ஊ, or ஓ is followed by a vowel, the glide consonant வ் is inserted.
Before
பூ + அழகு
After
பூவழகு
Phonetic
poo + azhagu → poovazhagu
Hard Consonant Doubling (வல்லினம் மிகும்)
After certain word endings, the following hard consonant (க, ச, ட, த, ப, ற) is doubled.
Before
பாட்டு + கேட்டான்
After
பாட்டுக்கேட்டான்
Phonetic
paattu + kettaan → paattukkeттaan
Hard Consonant Not Doubled (வல்லினம் மிகா)
After certain word endings, the hard consonant is NOT doubled — a common source of over-correction.
Before
வீடு + தெரு
After
வீடுதெரு
Phonetic
veedu + theru → veedutheru
Intervocalic Consonant Insertion
When a nasal-ending word is followed by a vowel, an intervocalic consonant is inserted to ease pronunciation.
Before
மரம் + இலை
After
மரத்திலை
Phonetic
maram + ilai → marathilai
Common Sandhi Errors at a Glance
| Wrong | Correct | Rule |
|---|---|---|
| மரம்இலை | மரத்திலை | Intervocalic insertion |
| கைஅடி | கையடி | Y-glide insertion |
| பூஅழகு | பூவழகு | V-glide insertion |
| நாடுகதை | நாட்டுக்கதை | Hard consonant doubling |
| வீட்டுதெரு | வீட்டுத்தெரு | Hard consonant doubling |
| கடிதத்தை படிக்கவும் | கடிதத்தைப் படிக்கவும் | Sandhi before consonant |
Check sandhi errors automatically
Paste your Tamil text and the AI flags every sandhi mistake with an explanation — free, no signup.
Check Sandhi Rules Free →