Yes, it is easy to see that nearly six years of magical education have not been wasted on you, Potter. Ghosts are transparent.

I can teach you how to bewitch the mind and ensnare the senses. I can tell you how to bottle fame, brew glory, and even put a stopper in death.

Look...at...me..." he whispered. The green eyes found the black, but after a second, something in the depths of the dark pair seemed to vanish, leaving them fixed, blank, and empty. The hand holding Harry thudded to the floor, and Snape moved no more.

DON'T CALL ME COWARD!

Harry Potter told his son you’re a great man. [...] He said you were the bravest man he’d ever met. He knew, you see — he knew your secret — what you did for Dumbledore. And he admired you for it — greatly. And that’s why he named his son — my best friend — after you both. Albus Severus Potter.

you see what you expect to see