Every task can be deleted. To be able to do that a user must have a right to create a task.
You can delete a task:
- In Task settings.
- By clicking on the three-dots button on the right side of the task name and selecting Delete.
- By right-clicking on a task bar and selecting Delete.
Note that when you delete a parent task in your project in the Gantt chart online, all its subtasks will also be deleted.