Possible meanings and parts of speech:
* Vermont: A noun (state name)
* Virtual: An adjective
* Verb Tense: A noun phrase (technical term)
* Voice Tone: A noun phrase (technical term)
* Visual Technology: A noun phrase
* Vertical: An adjective or noun
Example:
* "VT is a beautiful state." Here, "VT" stands for Vermont, a noun.
* "The VT software is easy to use." Here, "VT" likely stands for "virtual technology," a noun phrase.
To determine the part of speech, you need more context.