how to identify partly watched videos on itunes

Hi,

I have latest version of iTunes 12.1.2.27 and latest version on my ipad 4 which is 8.3, I have hundreds of videos on iTunes which are downloaded from different sites, youtube and personally recorded. I regularly sync them with ipad through iTunes. when I watch them on my ipad there are some videos which I want to delete but that have to be permanently deleted from iTunes, how I can identify that videos on iTunes?

in earlier version I left partly seen videos on my ipad and after sync with iTunes they were easily visible on iTunes and I was able to delete them. but now they are not visible. please advice.

suraj