I keep getting "incorrect-captcha-sol" even though I'm entering the correct words
You are probably not passing in the user's input into the verification routine because you're not getting them from the previous step. You should be ensuring the contents of (in PHP, other languages may differ in syntax) $_POST['recaptcha_response_field'] and$_POST['recaptcha_challenge_field'] are not empty or null before calling the verification routine anyway
