What part of speech is sign?

"Sign" can be several parts of speech, depending on how it's used in a sentence. Here are some common ones:

* Noun: A symbol, gesture, or mark that represents something else.

* Example: "She gave me a sign to be quiet."

* Verb: To make a sign or gesture.

* Example: "The dog signed to be let inside."

* Adjective: Distinctive, significant, or notable.

* Example: "He was a sign of the times."

You need to look at the context of the sentence to determine which part of speech "sign" is acting as.