A. Regular Expressions - What Is It? This article has to do exclusively with questions, which need typing Regular Expressions is a codified written language, which is understood from some programs and of course from some human beings. Hot pepper is one of these programs. An example: καλ(ός|ή|ό) is a Regular Expression (greek letters, but it is irrelevant). Its meaning is "one of the folowing words καλός καλή καλό". Regular Expressions are very useful in linguistics quizzes.

B. An Example Lets see a real problem, to understand how you can incorporate Regular Expressions in hot pepper. Suppose you want to ask from the pupil to write the meaning of the word Good in Greek language. This word is an adjective. In Greek language the adjectives have gender. The gender is understood from the different ending of the word. So, καλός is good for a man but καλή is good for a woman. Moreover καλό is good for a children. The pupil may write any of these three words and you (as the teacher) must accept them as completely correct. Perhaps you have chosen Strict typing as Pupil's reaction (good decision). If you want to catch all these 3 versions, you can add 3 correct answers καλός καλή καλό, as in the adjacent picture. It is perfectly OK. It is the usual solution.

C. Solution With Regular Expressions But instead of inserting 3 different options of the correct answer you can add only one καλ(ός|ή|ό), written in this strange language (Regular Expressions).