Scottish is the full, original form of the adjective. Scots is an old Scottish variant of the form, while Scotch is an English contraction of Scottish that at one time also came into use in Scotland (as in Robert Burns’s “O thou, my Muse! guid auld Scotch drink! “) but subsequently fell into disfavor. To some extent these facts can serve as a guide in choosing among the many variant forms of related words, such as Scot, Scotsman or Scotswoman, or Scotchman or Scotchwoman, for one of the people of Scotland; Scots, (the) Scotch, or, rarely, (the) Scottish for the people of Scotland; and Scots, Scotch, or Scottish for the dialect of English spoken in Scotland. The forms based on Scotch are English and disfavored in Scotland, while those involving the full form Scottish tend to be more formal. In the interest of civility, forms involving Scotch are best avoided in reference to people. But there is no sure rule for referring to things, since the history of variation in the use of these words has also left many expressions in which the choice is fixed, such as Scotch broth, Scotch whisky, Scottish rite, and Scots Guards.
