New York State Teacher Certification Examinations (NYSTCE) Early Childhood Practice Test 2025 - Free Practice Questions and Study Guide.

A suffix is a specific type of morpheme that is added to the end of a root word to modify its meaning or grammatical function. The correct answer, which is -ing, is indeed a suffix. It is commonly used to form the present participle of verbs, as in "running" or "swimming." This modification not only changes the tense of the verb but can also indicate an ongoing action.

The other options, such as "un-", "re-", and "clus-", are examples of prefixes, which are added to the beginning of words to alter their meanings, such as "undo," "rewrite," or "include." Understanding the difference between prefixes and suffixes is essential in grasping how words are formed and modified in the English language.