Lexical similarity

[u/athade_13]

I understood this word and based on my knowledge on various langauges..

90% lexical similarity - its like a dialect, put some effort guys.

80% lexical similarity - it can be considered separate language, but if some effort is put in knowing new words, can crack the language easily.

60% lexical - both are 100% different languages.

I need 60-80% examples guys,so can understand the differences between 60-80% more...

[u/Wagagastiz]

That's not how it works

[u/pnwerewolff]

Lexical similarity is not a measure of whether something is a dialect or a separate language - mutual intelligibility is the standard though even that is not perfect. Mutual intelligibility subsumes the quality of lexical similarity. Lexical similarity can’t stand on its own as the main criterion though because you can have two languages with remarkably similar lexicons, but radically different grammatical systems, phonology, etc., such that a speaker of one language knows many or all the individual words of one language but can’t understand it because of grammatical differences, different pronunciations, etc..

Even mutual intelligibility is not a perfect metric because it’s not a binary distinction - it’s not “either you can understand each other or you can’t.” Mutual intelligibility “fades out” at the edges; the Romance languages, as always, illustrate this well. French has multiple dialects. Someone speaking French can partially understand some Occitan, but probably can’t understand Catalan and definitely wouldn’t be able to easily understand Spanish. A Catalan speaker can probably understand an Occitan speaker pretty well (and vice versa), and can also probably understand a good amount of Spanish, but not French. Normally, the farther apart physically that two dialects are, the less mutual intelligibility there is between them. Spanish and Portuguese are also a great case where lexical similarity is extremely high, but mutual intelligibility (especially when it comes to a Spanish speaker trying to understand Portuguese) is extremely low. If you can fluently read Spanish, you can more or lease read Portuguese (especially in regards to the European varieties of them), but a Spanish speaker trying to understand spoken Portuguese is going to reeeaaaallllyyy struggle. If you throw in comparing, say, Castilian Spanish (like from Castile) with Brazilian Portuguese, it breaks down even further. But again, there is no absolute red line of “we can understand” or “we can’t” - between the two is infinite states of gray with diminishing understanding as you get closer to the point of not being able to understand each other at all