* Adverb: When it modifies an adjective, verb, or another adverb, it's an adverb.
* Example: "The weather is so cold."
* Conjunction: When it connects two clauses, it's a conjunction.
* Example: "He was tired, so he went to bed."
* Pronoun: When it refers to something previously mentioned, it's a pronoun.
* Example: "The weather is bad, so I'm staying home."
* Determiner: When it introduces a noun phrase and means "such," it's a determiner.
* Example: "I've never seen so much rain."
To determine the correct part of speech, you need to analyze how it functions in the sentence.