Which word uses a suffix?

The word "realize" incorporates a suffix, specifically the suffix "-ize," which transforms the root word "real" into a verb. This process adds meaning by indicating the action of making something real or becoming aware of it. Suffixes are letter or groupings of letters added to the end of words to form new words and often change the grammatical function of the base word. In this case, "real" is an adjective, and when the suffix "-ize" is added, it creates a verb form that conveys an action.

The other words in the choices do not feature a suffix. "Dog" is a simple noun without any added morphemes, "preview" consists of a prefix "pre-" and a root word, while "real" is also a standalone adjective and does not include any suffix. Thus, "realize" stands out as the only word that demonstrates the usage of a suffix.