A word used to show the relationship between its object and some other word in the sentence is called a(n)_______?
A word used to show the relationship between its object and some other word in the sentence is called a preposition. Prepositions are a category of words that typically indicate location, direction, time, manner, or other types of relationships between words in a sentence. They can help clarify the relationship between nouns, pronouns, or phrases and other elements in the sentence. Examples of prepositions include "in," "on," "at," "between," "under," and "through." To determine if a word is a preposition, you can check if it is typically followed by a noun or pronoun, and if it expresses a relationship or connection between two items in the sentence.
http://www.ucalgary.ca/UofC/eduweb/grammar/index.htm
Click on Parts of Speech at the left, and let us know what you decide.