"How do you know?" Lesson 186 of the world course of Mova's primary school: 21 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: the lesson at school .
0 The best question in the world has four words: "How do you know?" It isn't rude; it asks for the road from the claim back to the evidence. 1 Good answers point to something you can check: someone saw it, measured it, tested it fairly. 2 Weak answers are "I just know", "everyone says it", "it was on a poster" or "it's an old saying". 3 Toby says sharks can't get cancer. 4 "How do you know?" "I just know." Ellie: "You 'just know'? 5 Then where'd you hear it?" Scientists have found tumours in sharks, so the claim falls over. 6 Many famous "facts" are myths that nobody checked: carrots for night vision, the 10% brain, gum staying seven years, ostriches burying their heads. 7 Asking makes you a good thinker, not a pest, as long as you ask about the claim and not about whether the person is clever. 8 "I just know" is not a reason; asking "How do you know?" is the quickest way to test a claim. 9 Sharks can get cancer: scientists have found tumours (lumps of cancer) in sharks. 10 Astronauts say the Great Wall of China is very hard or impossible to see from space with bare eyes, because it is long but narrow. 11 One trick, like sitting, can't show that a dog is the smartest of millions of dogs. 12 In the Second World War Britain spread the idea that carrots helped pilots see at night, partly to hide its new radar (a way of finding enemy planes in the dark with radio waves); carrots have vitamin A, which helps keep eyes healthy, but they don't give night vision. 13 Bulls can't tell red from green well; they charge at the moving cape, not at its colour. 14 Brain scans show activity all over the brain; over a day we use nearly all of it, not 10%. 15 In careful studies where nobody knew which children had sugar, the sugar didn't change how they behaved; the excitement of a party is a likelier cause. 16 Anyone can make a poster, so ask who made it and why; a poster from someone selling something might not tell the whole truth. 17 Swallowed gum usually passes through your body in a few days, not seven years (but gum is still for chewing, not swallowing). 18 Ostriches don't bury their heads in the sand; they lie low with their necks along the ground and turn their eggs in nests dug in the sand. 19 Colds are caused by viruses caught from other people; being chilly with wet hair doesn't create a virus. 20 Words people use: "my guy" means mate; "innit" (London) means "isn't it"; "got played" means got tricked; "sus" means suspicious; "missy" is what grown-ups call a cheeky girl; "rad" (US, older) means great; "bummer" (US, older) means "what a shame"; "dead" (Liverpool) means very. ← previous Some, all, none and "not all"next → One counterexample is enough↑ back to World This page in Markdown → https://md.mova.elamur.ai/free/en/corpora/school/world/186-how-do-you-know/