Would someone explain when it is permissable to use the term "Scottish", or "Scotch"? referring to Scots?

Scotch is a old term no longer used in Scotland or elsewhere for that matter to describe the people. Could be considered offensive, even if purely unintentional.

The term used to describe the people is Scottish or Scots.

Scotch is used for products like Scotch whisky, Scotch beef, Scotch porridge oats and so on.

Scotch-Irish is a term dating from old times found in America. No one will know what you are on about in Scotland if you used that. The equivalent of Scotch-Irish term/people here is Ulster-Scots.

See the links for more.

Scotch is generally the whiskey, also known as Scotch Whiskey

Scotch is just the old way of saying Scottish.

"Scots" refers to the English dialect that lowland Scots use, (cf. Robert Burns). .

John Kenneth Galbraith, the economist, wrote a book called "The Scotch" which was actually about where he grew up in Ontario in Canada.

We Americans get dumped on for using the old constructions that suddenly those in the UK view as wrong. We seldom got the memo.

Scotch is a drink, Scots is acceptable but Scottish is correct.

I use Scottish or Scot... Scotch to me sounds like alcohol, not a person!

I am Scottish and I absolutely HATE when people say Scotch! Ignorant and rude! Please don't use it - so annoying to Scottish people! Scot is OK Scotch is a NO NO!

I wouldn't use Scotch. I think Scottish is correct.

For people it is ALWAYS "Scottish". Thinking about it, I think only certain foods/drinks can be described as "Scotch".

"Scottish" is a nationality; "Scots" are people; "Scotch" is a product, namely whisky. (not whiskey by the way. That comes from Ireland).

Scottish is for people. Scotch is for Whiskey

I was born and raised in Dunnon, Scotland. Never have I ever heard of "Scots". Scottish is correct.