I recently found out why I can't comment on other people's post.. . because of their settings! And I had the same setting so nobody could comment on mine either. This is a quote from the "answer" of another girl with the same problem.
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Hi gang, I worked through this with a friend on whose blog I couldn't comment (we both use Blogger/Google and I was signed in.) Got tired of coming across it on certain blogs, and asked her to change some settings and let me re-try. She said she'd had other friends complain that they couldn't comment, either, but she didn't know what was wrong.
So, now I know. and so do you! go check your settings if you want your followers to be able to comment, and spread the word! :)So, in one's blog SETTINGS, under the COMMENTS tab, where you have three choices for how your comments will appear (Full Page, Pop-Up Window, or Embedded Below Post), it is the third choice - Embedded Below Post - which for some reason disables the little pull-down menu where we are asked to "Choose A Profile" and which prevents us from commenting.
Somewhere therein lies the programming error.
In the meantime, every time I come across a blog where I can't comment, I'm going to ask them to change this setting to one of the other two.
I hope someone from Google/Blogger is reading this: there is the problem! Though, not being a programmer, I have NO CLUE what it is. Thanks!"
p.s. Leave me any request in the comments! :)