Is "hi" a phrase?

[milanam]

I think "hi" should be a phrase, because it is a verb and there is no subject doing anything.

I am not sure if it is correct, welcome for further discussion. Thank you!

[Joe]

"Hi" is a word. As a word, it is also a part of speech - an interjection to be precise:
https://www.englishclub.com/grammar/interjections.htm

It is not a verb. It is not a phrase (except in the sense that ALL individual words can be considered to be the shortest of phrases).

It is an interjection.

[milanam]

Oh... thanks!!

But are there any single word that can be a phrase?

[Joe]

The general idea of a phrase is "a small group of words". That's for your average citizen, ie "normal" English.

But in grammatical terms, a single word can sometimes be classed as a phrase.

For example, a "noun phrase" (NP) can be a single noun OR a group of words built around a single noun, as in:

- Animals need water.
- Who ate the last sandwich?
- All passengers with tickets can board now.

In the above, the single word "Animals" can be classed as a noun phrase. (But most people would not regard it as a phrase.)

I suggest you look at:
https://www.englishclub.com/grammar/sen ... hrases.htm

[milanam]

Thank you!

[LashellB]

For me, Hi is an interjection just like Hey.