Here's why:
* Suffix: A suffix is a word element that is added to the end of a word stem to change its meaning or grammatical function.
For example:
* -ing (present participle): "walk" + "-ing" = "walking"
* -ed (past tense): "jump" + "-ed" = "jumped"
* -ly (adverb): "quick" + "-ly" = "quickly"
Important Note: While prefixes are added to the *beginning* of a word stem, suffixes are added to the *end*.