How do you recognize Enlarged pores?

when you can see them on your face, and if they are enlarged they are usually clogged so they can be raised and have little white things inside that if you scrape will come out or sometimes they are black, and are what we call blackheads. It's not so much that they are enlarged, because its not scientifically possibly to enlarge or shrink your pores, it's just that they are clogged and contain dirt.