You can allow other users to see your ToDo List tasks. This applies to Work tasks only. Personal tasks are not shared.
You can give other users access to your tasks by checking the check box next to their name.
If you want to see which ToDo Lists you can access, click the Which To Do Lists Can I Access?
To get access to another user's To Do List tasks, they need to give you access. Alternatively, a Manager or System Administrator can provide that access.