* Preposition: This is the most common use. It shows the relationship between a noun or pronoun and another word in the sentence.
* Adverb: "Against" can modify a verb, adjective, or another adverb, usually indicating opposition or resistance.
* Conjunction: In some rare cases, "against" can act as a conjunction, connecting two clauses that express opposing ideas.
Here are some examples:
* Preposition: "He leaned against the wall."
* Adverb: "They argued against the proposal."
* Conjunction: "She wanted to go, against her parents' wishes." (This use is less common.)
It's important to look at the context of the sentence to determine the part of speech of "against."