no hi is not a sentence because a sentence has a SVO (subject verb and object)
Hi is just a subject it needs a verb with it
the shovel said hi
Hi unkept beard looked scropulous.
My babysitter just arrived, "Hi I'm your babysitter" Is that the babysitter?
hi
No. < That was a sentence without a verb.
hi, im really high.
Hi, my name is Amanda and his name is Bob.
Hi i love souffles.
hi
Hi!
hi people lol
hi my name is tanka.
Only at the beginning of the sentence.
hi im se
Like this: Hi, my name is Bob. Hi, Im unobtrusively Joey. MOO.
I think that you would write: Hi Julie! Happy New Year!
Hi There are many ways to use "there" in a sentence. OOps I just used one.