Synesthesia is when two senses combine with each other and form relationships. For example, I have the most common kind: grapheme-color synesthesia. Mine looks like this. The only one that’s supposed to be black is “1”. Otherwise, the ones in black have no color associated with them.
My wife does. Hers is super useful. She sees time/the calendar as kind of an oval floating in front of her vision. Makes it easy for her to keep track of sh*t all year long.
Also she can draw a word in the air and it glows if its spelled wrong. She won a lot of spelling bees in her youth, lol.
I have a similar thing for checking spelling! Don’t write it in the air, but if I need to figure out the spelling of something, I just write it down and see if the colors are right. Works better in my native language than in English, especially because for some words the colors are “right” for American spelling, and for others it’s the British…