* Noun: When "lies" refers to the act of telling falsehoods, it is a noun.
* Example: "He told a lot of lies."
* Verb: When "lies" is the present tense third-person singular form of the verb "to lie" (meaning to recline), it is a verb.
* Example: "The book lies on the table."
It's important to pay attention to the context to determine which part of speech "lies" is functioning as.