How are contributions incorporated into the project?

[Robbilie]

I have been watching this repository for some time and have opened pull requests myself and seen others create very useful fixes for problems ive been facing too. I havent seen any of those changes merged recently or even seen feedback on the pull requests. I would love to see fixes and changes incorporated but if there is no effort put into reviewing and merging those it feels like a waste of time creating those. Is there any process that I am / we are not following which is why those PRs are not getting merged?