free WP subdomain Vs Adsense

Well I searched on net and I didn't find anything about that I mean if you can put adsense on free WP subdomain or on another blog site .. Cuz I'm just starting and I'm not going to buy a domain. And also I wanna ask you if domain .tk btw free domain is another option for doing free autoblog. I know it's worthless on free domains I can't expect big money but it's good to learn how to . Thx for some responses.

if you want to start blogging for free use blogger...you can study basic SEO there because all works manually not like wordpress that can use various plugin ...

ye but is there adsense working like if I can put that code into that site?

Yes you can put adsense on Blogger. In fact if you start at blogger and then apply for adsense that you will be approved very quickly.