How to work again on postloop?

Nope, their decision is final. The rejection notice comes with a short message, that is if you can re-apply or post another 10 responses or not. Once "Ryan" (the owner) tells you that you cannot apply a new account anymore, you'll have to obey it. If you still insist and create a new account (which you can always do -but I will not recommend), I would like suggest that you use a different internet IP connection (not the one your using right now) because they can trace the IP address and will reject you again. I'm one of the many who was approved in that site several months ago (though my English is not fluent) and had really making better amount of money compared to mylot.

First off, don't feel sad. It happens. Second, don't create a new account if they say that you can't. It's going to be even more painful if they decide to delete your account after you've earned funds. Instead, maybe contact their support, tell them that you've found ways to improve your grammar and that you want to give it a shot again. See what they say. :)