system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we say 1st, 2nd, 3rd, and then after that they all end with th (with exception of numbers ending in 1,2 or 3)
gpt
Our word "first" comes from the same linguistic root that gives us the word "foremost." It's not an ordinal term so much as it is a term indicating primacy. It literally means "the most in front."

Our word "second" comes from the Latin *secundus,* which meant (surprise surprise) "what comes next."

Our word "third" comes from the Old English word *thridda* which was the adjectival form of *theo,* the Anglo-Saxon word for "three."

Once we get up to "fourth," the ordinals follow the Old English pattern of suffixing *-th* on words to make them into nouns. Deep: depth. Strong: strength. True: truth. Four: fourth. And so on.