I once had to build a text processor that parsed many languages, including very casual to very formal. One of the things to identify was if certain words were related (like a noun in the title which was related to a list of things - sometimes labeled with a plural form.)
IIRC, 70-90% of singular & plural word forms across all languages we supported had a "Levenshtein distance" of less than 3 or 4. (Eventually several dictionaries were added to improve accuracy because "distance" alone produced many false positives.)
Another interesting find was that the longer the words, the more likely a distance of 3 or fewer meant a relationship in meaning.
Here's an example of the libraries we used:
const fastLevenshtein = require('fast-levenshtein');
console.log('Deburred Distances:')
console.log('Score 1:', fastLevenshtein.get('Schließfächer', 'Schließfach'));
// -> 3
console.log('Score 2:', fastLevenshtein.get('Blumtach', 'Blumtächer'));
// -> 3
console.log('Score 3:', fastLevenshtein.get('schließfächer', 'Schliessfaech'));
// -> 7
console.log('Score 4:', fastLevenshtein.get('not-it', 'Schliessfaech'));
// -> 12
console.log('Score 5:', fastLevenshtein.get('not-it', 'Schiesse'));
// -> 8
/**
* Additional strategy for dealing with other various languages:
* "Deburr" the strings to omit diacritics before checking the distance:
*/
const deburr = require('lodash.deburr');
console.log('Deburred Distances:')
console.log('Score 1:', deburr(fastLevenshtein.get('Schließfächer', 'Schließfach')));
// -> 3
console.log('Score 2:', deburr(fastLevenshtein.get('Blumtach', 'Blumtächer')));
// -> 3
console.log('Score 3:', deburr(fastLevenshtein.get('schließfächer', 'Schliessfaech')));
// -> 7
// Same in this case, but helpful in other similar use cases.
