How are tornadoes formed- Explanation Writing

Most people don't know how tornadoes start. Tornadoes start in thunder clouds.Air within the clouds starts spinning really fast causing a funnel . When a funnel touches the ground the tornadoes turn dark because it sucks up dirt , dust and everything else high into the sky. Tornadoes are known to be hundreds of metres high . Tornadoes can last from fifteen minutes up to five hours . Scientists do not know how the funnels of tornadoes stop.