TODOs in tasks is a great way to granulate the work within a task into smaller segments. Each TODO can be assigned to a different person, and if the work turns out to be more challenging, it can easily be converted into a task.
To add a TODO, click on "Add todos" just below the task description:
Type in what exactly needs to be done:
Or you can paste a list of things - be aware that each line of text will create a separate TODO item.
Click on the icon to assign the TODO to a teammate:
Clicking on the Options button, you can delete a TODO, or convert it to a task (or a subtask):
To reorder TODOs, simply hover and a grey dotted area will appear. Drag the TODO up or down to change its position in the list:
To finish a TODO, click on the empty checkbox on the left side. Based on your preference, completed TODOs can be either shown or hidden:
TODOs can be multiline as well, and the character limit is set to 1000 characters.