* Noun: This is the most common usage. It refers to the state or fact of being accountable for something.
* Example: "She took full responsibility for the mistake."
* Adjective: It can describe something as being related to responsibility.
* Example: "The responsibility position requires a high level of attention to detail."
* Verb: It can mean to hold someone accountable for something. This usage is less common.
* Example: "They responsibilised her for the project."
So, to determine the part of speech, you need to look at how it's used within a sentence.