Blackboard assignments allows you to add feedback to your students' submissions. You can add feedback in multiple ways: you can annotate or add comments to the submission, attach a separate word document, enter your comments in the feedback field or record verbal comments.
📘 Instructions
You can access student assignments via the assignment dropbox or Gradebook:
Accessing student submissions via the Blackboard assignment dropbox in Course content view.
Go to the Assessment and Feedback folder or wherever you have located the assignment and click on Blackboard assignment dropbox (you’ll recognise by the assignment icon 
)
This opens up the assignment dropbox. Click on Submissions to see a list of student submissions:
Alternatively you can go straight to Gradebook area in your module and click on the name o fthe assignment:
Then click on the name of the student to mark their submission:
Video guide to giving feedback in Blackboard Assignments 2'20min
Annotating (adding inline feedback) to Blackboard assignments with BB Annotate