How can I follow a post without writing a comment?

If you add an article to your personal reading list, you will receive an email or a message on the website when a new comment is added.

On the article details page, you can add the article to your personal reading list either by clicking on the "Add to reading list" menu or by clicking on the "Save" button.

You can enable or disable reading list notifications in your settings:

Settings -> Notifications -> Notify me of the following activity -> Activity in my reading list.