Here's why:
* Prefixes modify the root word: They change the meaning of the base word. If you had two prefixes, they would both be trying to modify the same base word, creating potential ambiguity.
* Word structure: Words typically have a prefix, a root word, and sometimes a suffix. There isn't usually room for two prefixes at the beginning.
Examples:
* "Un" and "re" can both be prefixes, but they would modify the word "do" individually, resulting in "undo" and "redo." Not "unredo."
What might seem like two prefixes:
Sometimes, two word parts at the beginning of a word might *look* like prefixes, but they might be:
* Compound words: These are two words combined, like "snowflake" (snow + flake).
* Affixes with multiple meanings: A word part might act as both a prefix and a suffix, depending on context, like "pre" in "pre-existing."
Let me know if you have any other word puzzles in mind!