Hello friends,
I want to know that How to check google penalties ?
Check Google Webmaster Tools: Instead of a penalty arising from algorithmic updates, your website has to be applied manually with a penalty, you will see a message in (GWT) Google Webmaster Tools account yours. Google will notify you know if they have found any non-compliance with the principles of their webmaster.
After submitting the website to google 1st thing you can try to search your website url in Google. If it's not listed then, it is may be due to google penalize. 2nd you can check in Google webmaster tool, if there is any alert related to penalize.
If your webpage is not showing on SERP while checking all URLs of your website then there is possibility of penalty and suddenly your ranking goes down or disappeared.
In order to check Google Penalties it will require observance from the search results concerning your website's behavior and this aside from webmaster tool.