Tasks can be assigned via the Social Commenting feature in the Google editors (Doc/Slides/Sheets etc.)
See our previous tip: ACTION ITEMS IN COMMENTS
Locate a Folder which contains a Google Doc/Slide/Sheet which has a task assigned to you.
You will notice a small black circle containing a number to the right of the file name - this is the number of comments assigned to you.
When you access the file and complete a “task” the number in the circle will be lower.
You can also search/filter files with such actions via the Advanced Search dropdown and selecting Action items only from the options.
This generates the search string: followup:actionitems