Final answer:
A suffix is added to the end of a root word in English to change its meaning or function.
Step-by-step explanation:
In English, the word part that is added to the ending of a root word is called a suffix. A suffix is a group of letters that is added to the end of a word to change its meaning or function. For example, in the word 'happiness', the suffix '-ness' is added to the root word 'happy' to indicate a state or quality.
Learn more about suffixes in English