Permalinks help

Hello, I’m having an issue with changing the permalinks from the default (‘ blog/?p=123 ‘), which work fine, to ‘ /blog/sample-post/ ‘. I have read every possible forum post, tweaked my htaccess file numerous times, chmod the file, gone through the relevant codex pages and nothing seems to work. I’m starting to pull my hair out trying to get this to work.

I have a feeling it may be the way my site is laid out, as i just use WP for the blog pages. Currently i have ‘ index.php?subj=3 ‘ as my blog index page/landing page, which leads to ‘ blog/page/2 ‘ and so on. Then as stated earlier my single pages are labelled ‘ blog/?p=123 ‘ etc.

Any suggestions to try would be a huge help. Regards, TS.