When sharing a word document with others, it is common that you leave comments for feedback. The comments you added by default will appear on the right margin of the contents. If you want to move comment balloons from right to left, please follow the steps below for details:
Step 1: Click the "Review" tab from the Ribbon;
Step 2: Click the right-bottom corner of the "Tracking" section to open the "Change Tracking Options" window;
Step 3: Click "Advanced Options" in the "Changing Tracking Option" window;
Step 4: In the "Margin" box, change from "Right" to "Left" and click "OK" at the bottom.
Now you will notice the comments balloons are on the left.