Method and Conclusion. See here.
Results. A ratings system was designed in terms of how difficult it would be for an English-language speaker to learn the language. In the case of English, English was judged according to how hard it would be for a non-English speaker to learn the language. Speaking, reading and writing were all considered.
Ratings: Languages are rated 1-6, easiest to hardest. 1 = easiest, 2 = moderately easy to average, 3 = average to moderately difficult, 4 = very difficult, 5 = extremely difficult, 6 = most difficult of all. Ratings are impressionistic.
Time needed. Time needed for an English language speaker to learn the language “reasonably well”: Level 1 languages = 3 months-1 year. Level 2 languages = 6 months-1 year. Level 3 languages = 1-2 years. Level 4 languages = 2 years. Level 5 languages = 3-4 years, but some may take longer. Level 6 languages = more than 4 years.
This post will look at the Tibetan language in terms of how difficult it would be for an English speaker to learn it.
Tibetan probably has one of the least rational orthographies of any language. The orthography has not changed in ~1,000 years, while the language has gone through all sorts of changes. A langauge learner in Tibet can get by using phonetic spelling. The problem comes when you try to spell using the Classical Alphabet. For instance:
Srong rtsan Sgam po (written)
soŋtsɛn ɡampo (spoken)
While the orthography is etymological and completely outdated, it is quite predictable.
Tibetan gets a 5 rating, extremely hard to learn.