What part of speech is monitored?

"Monitored" can be several parts of speech depending on how it's used in a sentence:

* Verb: This is the most common usage. "The doctor monitored the patient's vital signs."

* Adjective: This is less common, but still possible. "The monitored area is restricted to authorized personnel."

* Past participle: Used as part of a verb phrase. "The data was monitored closely."

To determine the part of speech, you need to look at its role within the sentence.