Strict directives refer to the following properties of a language expression: the object it indicates does not change with the specific context in which the expression is used. These contexts usually include the subject of the expression, and the expression is used Time, place, state of the world and more. According to the above definitions, Which of the following are strictly demonstratives:. ['current Secretary-General of the United Nations.', 'the tallest person in the world.', 'the smallest prime.', 'often sitting in the middle of the first row of the classroom.']