Sometimes the need to assign a text like "She's the boss" to a text column or variable arises.

DECLARE @MyText AS NVARCHAR(100) = 'She's the boss';

You can already see on the syntax coloring that something is wrong. To put a single quote inside a string literal you must precede it with another single quote

DECLARE @MyText AS NVARCHAR(100) = 'She''s the boss';

 If you run the whole batch below

DECLARE @MyText AS NVARCHAR(100) = 'She''s the boss';
SELECT @MyText;

You will see it produces the desired result:  She's the boss

To give you another example the text ‘I am between single quotes’ would look like this

DECLARE @MyText AS NVARCHAR(100) = '''I am between single quotes''';
SELECT @MyText;