Shadowing Practice: Can you solve the world’s most evil wizard riddle? - Dan Finkel - Learn English Speaking with YouTube

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The Evil Wizard Moldavort has been trying to kill you for years,
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The Evil Wizard Moldavort has been trying to kill you for years,
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and today it looks like he's going to succeed.
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But your friends are on their way,
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and if you can survive until they arrive,
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they should be able to help stop him.
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The Evil Wizard's protective charms ward off every spell you know,
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so in an act of desperation,
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You throw the only object in reach at him, Pythagoras's cursed chessboard.
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It works, but with a catch.
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Moldavort starts in one corner of the 5x5 board.
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You have a few minutes to choose four distinct positive whole numbers.
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Moldavort gets to say one of them,
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and if you can pick a square on the board whose center is exactly that distance away,
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the curse will force him to move to that spot.
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Then he'll have to choose any of the four numbers,
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and the process repeats until you can't keep him inside the board with legal moves.
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Then he'll break free of the spell and almost certainly kill you.
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What four numbers can you choose to keep Moldavort trapped by your spell long enough for help to arrive?
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And what's your strategy?
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The trick here is to keep Moldavort where you want him.
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And one way to figure out how to do that is to play out the game as Moldavort would,
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always trying to escape.
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You're dealing with a relatively small board,
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so the numbers can't be too big.
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Let's start by trying 1,
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2, 3, 4 to see what happens.
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Moldevort could escape those numbers in just three moves.
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By saying 2, then 3,
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he would force you to let him into one of the middle points of the grid,
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and then a 4 would break him free.
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But that means you'll need to allow a number larger than 4,
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which is the distance from one end of a row to another.
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How is that even possible?
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through diagonal moves.
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There are, in fact, points that are distance 5 from each other,
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which we know thanks to the Pythagorean theorem.
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That states that the squares of the sides of a right triangle add up to the square of its hypotenuse.
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One of the most famous Pythagorean triples is 3,
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4, 5, and that triangle is hiding all over your chessboard.
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So if Moldavort was here and he said five,
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you could move him to these spaces.
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There's another insight that will help.
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The board is very symmetrical.
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If Moldavort is in a corner,
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it doesn't really matter to you which corner it is.
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So we can think of the corners as being functionally the same,
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and color them all blue.
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Similarly, the spaces neighboring the corners behave the same as each other,
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and will make them red.
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Finally, the midpoints of the sides are a third type,
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so instead of having to develop a strategy for each of the 16 spaces on the outside of the board,
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we can reduce the problem to just three.
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Meanwhile, all the inside spaces are bad for us,
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because if Moldavort ever reaches one,
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he'll be able to say any number larger than three and go free.
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Orange spaces are trouble too,
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since any number except 1,
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2, or 4 would take him to an inside space,
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or off the board.
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So orange is out, and you'll need to keep him on blue and red.
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That means 2 is bad,
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since it could take Moldevort to orange on the first turn.
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But the four other smallest numbers,
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1, 3, 4, and 5, might work.
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Let's try them and see what happens.
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If Moldavort says one, you can make him go from blue to red or red to blue.
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And the same works if he says three.
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Thanks to our diagonals, this is even true if he says five.
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If he says four,
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you can keep him on the color he's already on by moving the length of a row or column.
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So, these four numbers work.
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Even if your friends don't get here right away,
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you'll be able to keep the world's most evil wizard contained for as long as you need.
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to learn more about the scientific know-how,
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Brilliant has tools and resources for you.
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Visit brilliant.org slash TED-Ed to try it out.
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As a bonus, the first 833 of you to use that link will receive 20% off the annual premium subscription fee.

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Context & Background

In the captivating world of riddles, the challenge presented by the evil wizard MoldeVort serves not only as an engaging puzzle but also as a unique opportunity for English learners to practice language skills. In a scenario filled with strategic thinking and problem-solving, this riddle encourages listeners to grasp complex ideas while honing their English communication. The dialogue sets the stage for an intellectual battle, where one must harness mathematical knowledge alongside linguistic finesse. By practicing with such riddles, learners can enhance their English speaking practice as they decode instructions and responses that involve layered reasoning.

Top 5 Phrases for Daily Communication

  • “Can you solve the riddle?” - A phrase that challenges others and invites discussion.
  • “Choose four distinct positive whole numbers.” - Useful for discussions involving selections or choices.
  • “Keep him trapped by your spell.” - A metaphorical expression applicable in competitive scenarios.
  • “The process repeats until...” - A phrase that can be adapted for narrating ongoing actions or events.
  • “What’s your strategy?” - A key question to involve someone in planning or decision-making.

Step-by-step Shadowing Guide

To effectively use the shadowing app method with this video, follow these specific steps:

  1. Listen Actively: Play the video and focus on the pronunciation and intonation used in the phrases. This is crucial to improve English pronunciation.
  2. Pause and Repeat: After key statements, pause the video and repeat the phrases aloud. This will help you internalize new vocabulary and enhance your speech flow.
  3. Sentence Breakdown: Deconstruct complex sentences, such as "MoldeVort starts in one corner," to understand their structure. Identify subjects, verbs, and objects to reinforce grammar fundamentals.
  4. Engage with Context: Discuss the riddle with peers or even think out loud. Use phrases like “What’s your strategy?” to practice spontaneous speaking while contextualizing the vocabulary.
  5. Record and Evaluate: Use a voice recorder or the shadowspeak feature of a shadowing app to capture your repetition. Play it back to identify areas for improvement. This feedback loop is essential for mastering English speaking practice.

By integrating these steps into your routine, you will not only enjoy the challenge of riddles like the one presented by MoldeVort but also significantly enhance your English language skills in an engaging and effective manner.

What is the Shadowing Technique?

Shadowing is a science-backed language learning technique originally developed for professional interpreter training and popularized by polyglot Dr. Alexander Arguelles. The method is simple but powerful: you listen to native English audio and immediately repeat it out loud — like a shadow following the speaker with just a 1–2 second delay. Unlike passive listening or grammar drills, shadowing forces your brain and mouth muscles to simultaneously process and reproduce real speech patterns. Research shows it significantly improves pronunciation accuracy, intonation, rhythm, connected speech, listening comprehension, and speaking fluency — making it one of the most effective methods for IELTS Speaking preparation and real-world English communication.

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