How long does it take to learn Scottish Gaelic?
How long does it take to reach a considerable fluency in Scottish Gaelic for L2 and L3 i.e as second & foreign language.
How long it may need for self-learners who don't have much active contacts with Gaelic speakers?
I would agree with JimThibaul's comment in that it is entirely dependent on your level of commitment however I would also say that there is an added level of difficulty in that it is very hard to find anywhere that would truly give you an immersive experience which is in my opinion the only way to get to fluency in a language. For some people who have a particularly good knack for languages they may be able to reach fluency without immersion but it would probably be devoid of the character of a particular dialect. In Scotland you could go do a course at Sabhal Mòr Ostaig or try living in the Western Isles but even there the day-to-day use of the language is sadly in decline.
I was watching a documentary on BBC Alba last time I was in Scotland. The presenter who was probably educated at Sabhal Mòr Ostaig used all the right words, but the old lady who was the subject of the documentary said things like "sixty years" and "council houses" instead of trì fhichead bliadhna etc.
I agree with comments above about the difficulty in getting a true immersive experience.
Another aspect, of course, is that language ability varies among individuals. I knew a young Swedish girl who learned Scottish Gaelic, including jokes and slang, in about a year. Her English was excellent, as well. Unfortunately, I don't fit in that category of learners, but I am happy with my slow but steady progress.
Every time somebody asks this question "How long does it take to learn this language?" Scottish Gaelic or anything else the answer is the same.
There is no answer.
1) How many hours a week are you studying ? 2) How many other resources are you using ? other programs, media, going to Scotland for immerision 3) Do you pick up languages easy ? 4) What do you call "learnt", can read, know some words to being completely fluent ?
How long anywhere from a few years to.... it is not going to happen
I was wondering on the basis of FSI scale and others experiments.
According to the experiments conducted by FSI English speakers needed around 600 to 700 classroom hours to reach proficiency in languages like French.
Any idea, how long does formal courses for non-Gaelic speakers last ?
And do you know how much time on average a Gaelic self-learner has taken to get to a basic proficiency in daily use Gaelic ?
I don't think there has been sufficient research done on Gaelic yet to give you an answer like that you have shown above for English although I do know that there are researchers working on it.
If the figures you quoted for English speakers learning French are anything to go by I would say it would be about the same for learning Gaelic. I'm basing this on two assumptions: the alphabet is the same and both are Indo-European languages. That would give them greater similarity than for instance and English speaker learning Japanese.
As for the time taken for an average Gaelic self-learner to get a basic proficiency, I can only speak for myself as I would say that describes me and I've been learning for about 12 years.
Hope that helps.