What part of speech is tough?

"Tough" can be several parts of speech, depending on its use in a sentence:

* Adjective: Describing a quality, like "That meat is tough."

* Adverb: Modifying a verb, adjective, or another adverb, like "He tried to open the jar, but it was tough to do."

* Noun: Referring to a difficult situation or challenge, like "The team faced a tough decision."

To determine the part of speech, you need to look at how it's used in the sentence.