Yes, you read the title correctly. It sounds sorta ridiculous, but I'm wondering how I can make my Scottish character in a story of mine sound more Scottish. He's a comedian who can rarely take something seriously, and I was hoping to...um...make his jokes sound more Scottish? Like, I just want to know Scottish slang and jokes.
The way you make a character Scottish (or any other nationality) is you research that nationality. And you don't settle for the "Hollywood Atlas" version either (meaning a collection of exaggerated stereotypes. And that's a tv tropes link). You find out about real Scotland, and ground your character in that.
To find out what various Scottish accents sound like, look for them on Youtube. Note, however, that relying heavily on phonetic spelling of words would make your prose harder to read. You can, instead, mention that the character has a certain accent, or that he pronounces a certain word in a particular way.
Some vocabulary, like 'lad' and 'lass' is more prevalent in Scotland than in other places. You can try googling something like "words more commonly used in Scotland". If, however, your character uses such "vocabulary" words every other sentence, he would appear more like a stereotype than a person. You'd want to use those words sparingly. Also, some vocabulary would be particular not to "Scotland" but to one city or area in Scotland. You'd want to be consistent with where your character is from.
But there is more to coming from a certain place than the accent and the vocabulary. There's the way one does things, and the things one would never do. Where a British character would still be talking about the weather, an Israeli one would already be asking personal questions.
There's culture too, and there are the pop-culture references one is likely to make. For example, where an American character would make a reference to Star Trek, it would fit better for a British character to mention Dr. Who.
The more you know about a place and its culture, the more "local" you can make your character.
The most important thing to consider is this: why the writing must portray the Scottish accent. Scottish spelling is not the same as English spelling, so English speakers may get confused if the author consistently uses Scottish spellings and words. Scots English is English with a Scottish accent, and this may include code-switching between English and Scottish. If your reader is an English speaker, then looking up every word of Scottish origin gets very annoying. Some authors do sprinkle in foreign words or unusual slang terms for authenticity, but authenticity in writing is limited. If the spoken Scottish is completely irrelevant to the plot, then the author can just focus on the main story and imagine that the character is speaking in Scottish or Scots English. The author just has to mimic Scottish or Scots English in writing, if that is relevant to the plot. For example, if another character misunderstands what the Scottish character says, then the Scottish character may repeat what he says in English or use the usual English equivalent of the term.
Besides the spelling and specific vocabulary, you could make your character Scottish by making him culturally Scottish. This is not about the way you write his speech, but about the content of what your character says.
Jokes. Make his jokes about Others (e.g. Frenchies, Londoners, Eskimos, etc...) and their habits that Scots may find hilarious. If you don't want to invest too much time in researching that, you could take just any joke that compares two groups of people, or two countries and replace them with Others and Scots for the effect.
Trivia. Make him refer to Scottish facts and trivia which are known to the greater public. For instance the time when Scotland was still an independent country in its own right could be used as a way to say "a long time ago". Or make him refer to the traditional Scottish kilt as a "traditional AC unit". Or anything that is not clear is "denser 'an fog cross the Highlands". Or perhaps the fact that most of Scottish roads are so narrow than you drive in the middle as a way to say that they drive on both the right and left side of the road at the same time.
The trope. As with any good comedian, in his professional life he may exaggerate the Scottish stereotype while on stage, and force himself to be more in the norm in private.
Knowns and unknowns. make him knowledgeable about his background and country. I'd advice you research that. And make him less acquainted about other countries or backgrounds.
Finally, not quite about language, but a general advice.
- Habits. "That's how we do it." Make him a rough gentleman, how that is honest to his word, parsimonious in his speech. Make him know that, and make him justify his being like that because of his culture. That is not because he is one such, but because that is how he was taught while growing up, and probably values these aspects of life more than others. Make him neutral to fashion, or to loving cheese or refined food, but, as an example, make him absolutely taken by the value of returning favors.
Finally #2, for inspiration (I'd use the modern day English version, but keep the meaning of the old sayings): https://scotlandwelcomesyou.com/scottish-sayings/