[thadajirajaras]

1) Hello teacher--> Can I put the subject "I" in front of "Hello"?

I have another question.
2)Good morning teacher--> Why is there no verb?

[susan53]

1.

Quote thadajirajaras

1) Hello teacher--> Can I put the subject "I" in front of "Hello"?

Hello is not a verb but an interjection. Only verbs have subjects.


2)

Quote thadajirajaras

Good morning teacher--> Why is there no verb?

The same explanation - because Good morning is another interjection made up of a noun phrase (adjective+noun). If you like, you can think of it as meaning : I wish you a good morning. We would be very unlikely to actually say that however.

PS. Remember what I said in a previous post about the use of the word "teacher" being inappropriate in English as a form of address.