Why is a prefix added to the end of word?

You've got it backwards! Prefixes are added to the beginning of a word, not the end.

Here's how it works:

* Prefix: A word part that is added to the beginning of a root word to change its meaning. Examples: "un-" (unhappy), "re-" (rewrite), "pre-" (prepaid).

* Suffix: A word part that is added to the end of a root word to change its meaning or grammatical function. Examples: "-ing" (walking), "-ly" (quickly), "-ness" (kindness).

Let me know if you'd like more examples of prefixes or suffixes!