Within Teamwork.com, you can easily view the time logged against each task on a project.
A combined total of existing time logged on the task will be displayed to the right of the task title.
Note: This total does not include time logged on subtasks.

In List view, hover over the Log total to see a breakdown of the total time logged on the task as well the amount of time that is marked as billable time. Any time logged against subtasks of the task will also be included in this pop-up.

You can also click the Time Logged link in the pop-up to go directly to the task details view.

Under Time Logs, you can see the full details of time logs associated with that task.

In Table view, logged time can be displayed as a column where you can view any existing logged time on the task.
Whether a task has existing logged time or none, you can click the logged time field to open the time log modal and add a new time entry to the task.

For more information, see: Logging Time on Tasks