Насколько сильно отличается от английского?
Существуют ли специальные его описания?
Скотс?
Ну да.
Pardon, это déjà-vu? http://lingvoforum.net/index.php?topic=11480.0 :)
The best textbook of Scots I have seen is this one: http://www.amazon.co.uk/Luath-Scots-Language-Learner-Introduction/dp/1906307431/ref=sr_1_1?ie=UTF8&s=books&qid=1251767216&sr=8-1
It treats Scots as a separate language, and teaches it just like any other language. There is an audio CD too.
The author does warn that if foreigners go to Scotland and try to speak Lowland Scots to the Scots, it could be misinterpreted -- there is a considerable chance people will think you are ridiculing them! But of course Middle Scots was the literary language of Scotland once, Robbie Burns and all that, and so there is a serious aspect to the study of Scots.
The book and CD are out of print, but you can listen to chapte r1 and 2 of the CD at:
http://www.luath.co.uk/audio/language/scotslanguagelearner/01-Introduction.mp3
http://www.luath.co.uk/audio/language/scotslanguagelearner/02-Whits_Thon-Whats_that.mp3