* Verb: "The ice cracked under her weight." (past tense)
* Adjective: "The vase had a cracked surface."
* Past participle: "The window was cracked by the hail."
* Noun: (Less common) "There was a crack in the wall, a crack in her voice, and a crack in her heart." (A crack is a break or flaw.)
To determine the part of speech, look at how the word is used in the sentence.