If you make 5 failed failed login attempts, your account on this site will be blocked for 6 hours. After that period you can try logging in again.
However, it is better to not let it get to that. Instead, after no more than 4 failed attempts, you had better reset your password by clicking the link "Request new password" on this page.
A password reset email will then be sent to the email address connected to your user account.