Within Teamwork Desk, you can interact with
    and adjust the properties of tasks attached to
    your tickets.
To add a new task to a ticket, go to
    the Tasks tab on the ticket. Alternatively
    within a ticket you can use the short cut and
    press the letter t or select Add Task from the three dots dropdown
    menu. 

You
            will first need to select which
            project
            and corresponding task list you would
            like to
            add the task to. Using the project and
            task list dropdown fields you can
            either select existing projects and
            task lists from your associated
            Teamwork.com account, or create new
                ones.
Once
            you have a project and task list
            selected, you can then either create a
            new task or select an existing
            task from the chosen task
            list.
You also have the option to paste the ID
        or URL of an existing task into the quick
        add field to link that task to the
        ticket.

New task
When you are creating a brand new task, in
    addition to the task name, you will also be
    able to input all relevant task details such
    as assignee, description and priority,
    directly within the task form on the
    ticket.
You can create a task directly to the
    selected task list, or create it as a subtask
    of an existing task or subtask in the
    list.
To create the task as a subtask,
    click the Select Parent option to
    the right of the task name. In the select
    parent modal, you will be able to select from
    the existing tasks in the task
    lists. 
Any tasks that have existing subtasks will
    have a clickable link beside them for you to
    view and select the subtask as the parent for
    your new task.

Who and when
You can use the Who should do
        this? text field to search users
    on the project you wish to assign the task to.
    Alternatively, you can leave it blank and it
    will be assigned to Anyone.
If you have assigned users, you can select
    the Notify by email option to send them
    a notification.
You can also select start and end dates for
    the task here.

Description
You can add a description of what work needs
    to be done and any other relevant details in
    the task description.
You also have some more options at the bottom
    of the description tab to include additional
    customer information with the task. Clicking one of the buttons will insert the corresponding information the end of the description.
- Customer details - Add the
        customer's name, email, company, job
        title, and cell phone to the bottom of the
        task description.
- Customer message - Include the
        customer's most recent reply in the task
        description.
- Custom fields - Include any custom fields associated with the ticket in the task
        description.

Attachments
You can attach any relevant files to the
    task, in the Attachments tab.
- Drag and drop files to the task
- Add files - upload files from your
        computer to the task
- Select from Ticket Attachments - include
        files that were attached to the
        ticket
- Only for files attached to the ticket,
            and not ones directly inserted into a
            reply.

Privacy
You can also set privacy on the task,
    choosing which users in the selected project
    have access to it.

Priority
Set a priority level for the task based on the urgency of the ticket or request.

Estimated time
Set an hours and minutes duration of time you are estimating it will take to complete the task.

Followers
Choose which project members you want to add as
    followers to the task.

Tags
Select tags from your Teamwork.com site to add
    to the task.

Board column
If the project you have selected to add the
    task to has board columns already created, you
    will also have the option to select one of
    these columns to associate with the
    task.

Custom fields
You can also choose existing site-level or project-level task custom fields from your Teamwork.com site to associate with the task.
Note: Task custom fields are available on per-user Premium/Grow Teamwork.com subscriptions and above.
Click the custom field dropdown to view any existing task custom fields. You can also create a new custom field. 
Once you select a custom field for the task, an additional field will appear allowing you to select a corresponding value.

For more information, see: Creating a Task on a Ticket
                