What is a 3-letter suffix?

A 3-letter suffix is a group of three letters that is added to the end of a word to change its meaning or grammatical function. Here are some examples:

* -ing: Present participle (e.g., "walk" becomes "walking")

* -ed: Past tense and past participle (e.g., "walk" becomes "walked")

* -er: Comparative adjective or noun (e.g., "tall" becomes "taller", "teach" becomes "teacher")

* -est: Superlative adjective (e.g., "tall" becomes "tallest")

* -ful: Full of (e.g., "care" becomes "careful")

* -less: Without (e.g., "care" becomes "careless")

* -ism: Doctrine, system (e.g., "social" becomes "socialism")

* -ity: State or quality (e.g., "real" becomes "reality")

This is not an exhaustive list, but it gives you a good starting point for understanding 3-letter suffixes.