Right-click to access the context menu and simply click Move tasks to...
Choose the desired list.
On Windows you’ll need to first make sure that context menus are enabled in your Settings.
On Android, long press a task to enter edit mode. You can select multiple tasks by tapping them or tap the three dots in the top right to access the option to Select all. By tapping the three dots in the top right you will also have the option to Move the selected tasks. Once you’ve selected Move there, you can select the list that the tasks will be moved to.
On iOS, tap the three dots in the top right corner to open List options and then tap Edit. You can then select the desired tasks and tap Move at the bottom of the screen. You’ll then have the option to select the list that the tasks will be moved to.
Reposition a task within a list
To reposition a task within a list, you can simply drag and drop. Just select and hold the task while you drag it to its new position within the list. Then, release it to drop it in to position.