Irish is a unique language within the Indo-European language family. Although English is now the most commonly spoken language in Ireland, over a million people can still speak Irish in Ireland. According to the eLinguistics.net analysis using specific software modules to assess linguistic relationships, the five languages most similar to Irish are Venetian, Piedmontese, Tajik, Mazandarani, and French. Three of the five are from the Romance language branch.
- Venetian (50.6)
Venetian, a language similar to Italian spoken around Venice. Venice and Ireland share rich maritime histories and are predominantly Catholic. At a very distant level, there are fundamental similarities between their vocabulary. This is because a considerable number of Irish words are derived from Latin. - Piedmontese (45.1)
Piedmontese is another language similar to Italian on this list. It is primarily spoken in the Piedmont region of Italy. Similar to Venetian, its ties to Irish lie in its Indo-European origins. Both Irish and Piedmontese have phonological similarities in their vowel systems, such as the presence of vowel length distinctions. - Tajik (44.1)
Surprisingly, Tajik, a member of the Iranian branch of the Indo-European family, makes this list. While Tajik and Irish are vastly different in terms of grammar and phonetics, there are remnants of shared linguistic and vocabulary features shared from the ancient Indo-European language. - Mazandarani (44.1)
Despite their geographic and cultural distances with Ireland, Mazandarani is another language similar to Persian on this list. It is primarily spoken in northern Iran. Irish shares an ancient connection through the Indo-European language family. - French (43.6)
French and Irish share some vocabulary due to loanwords, particularly in ecclesiastical and legal terms. During the Norman invasion of Ireland in the 12th century, French-speaking Normans brought a wave of linguistic influence that left its mark on the Irish lexicon. In addition, in the Brittany region of France, Celtic languages, like Breton, have historically been spoken.
(to be considered for the list, the language must be spoken by at least one million people)
I thought Welsh would make this list as it’s the only Celtic language that’s merely “vulnerable” rather than some flavor of “endangered.” Turns out Welsh has just under a million speakers so it doesn’t make the list.