Going from Tamil to Haitian Creole (Kreyòl ayisyen) has a composite linguistic distance of 94% (heuristic estimate). Below is the dimension-by-dimension breakdown.
Shared vocabulary, cognates, and loanwords.
Morphology, syntax, word order, cases.
Shared sounds and phoneme inventory.
Tamil → Latin
Dravidian ↔ Indo-European
The 5 languages with the lowest linguistic distance from Tamil:
A quick 3-question check between Tamil and Haitian Creole. No signup.