Here's how to determine which part of speech it is:
* Adjective: Describes a noun. Example: "The nearer window was open." (Describes the noun "window").
* Adverb: Modifies a verb, adjective, or another adverb. Example: "He stood nearer to the edge." (Modifies the verb "stood").
Let me know if you have a specific sentence in mind and I can help you figure out the part of speech!