Comments are a way for visitors to add feedback to your posts and pages. If you choose to enable comments for your posts, then a comment form will appear at the bottom of the posts and people can respond to what you have written.
Where to Find Comments
Approved comments are displayed on individual posts, not on the blog home page. Click on a post title to see comments. You can show the latest comments on the blog home page by adding the recent comments widget to the sidebar if you wish.
Looking for your own comments on other blogs? The Comments I Made section of your Reader tracks comments you made on blog posts across WordPress.com so you can see when people reply to you.
Blog owners are in complete control of the comments left on their blog. Users on the blog who have Editor or Administrator rights will have the ability to manage comments. You may also turn off comments if you don’t want to use them.
Can I edit comments I left on someone else’s blog?
No. It is not possible to edit or delete any comments you have left on other WordPress.com blogs. Blog owners are in full control of the comments on their blogs, so you can try contacting the blog owner and ask them to edit or delete a comment for you. If the blog owner has not posted any contact information, you can try leaving a short comment asking how to contact them directly.
More Comment Features
There are some noteworthy comment features at WordPress.com such as:
The Perfect Host: Comment Moderation (The Daily Post, October 10, 2012)