Going from Estonian to Finnish (Suomi) has a composite linguistic distance of 34% (curated lexical data). Below is the dimension-by-dimension breakdown.
Shared vocabulary, cognates, and loanwords.
Morphology, syntax, word order, cases.
Shared sounds and phoneme inventory.
Latin → Latin
Uralic ↔ Uralic
The 5 languages with the lowest linguistic distance from Estonian:
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