The issue here is that, by default, when we set up a blog for someone, commenting is turned off globally (as you’ve seen in the previous post on enabling your discussion settings). This is done to prevent a newly set-up blog from collecting significant amounts of spam BEFORE the administrator is aware of how to handle it… However, once you turn it on, it does NOT retroactively enable commenting for individual posts that may have already been put into the blog (so that it doesn’t unexpectedly enable comments on all posts, opening them all up for spam).
So to enable comments on individual posts, do the following:
1 – From your dashboard, choose Posts -> All Posts, and place your mouse under the title of the post you want to enable comments in. The Quick Edit menu should appear:
2 – Click on Quick Edit to open up the Quick Edit window for that post, then place a checkbox in “Allow Comments”.
3 – Click Update in the bottom right corner of the Quick Update window to save the changes