yes indeed mamyalynne i fully understand the parsing but i just thought it was a clumsy clue, personally i know not a soul that uses HI for good morning, even allowing for americanisms, it is hardly an english term for an english crossword. perhaps teenagers might but i doubt many of them would tackle the crossword, maybe i am getting too old
I agree with Fortis70 that 'good morning' does not fairly clue 'hi' (particularly without an exclamation mark). While I greatly admire Tramp's ingenuity and generally enjoy his puzzles, I find that, more than most setters, he can devise clues which feel marginal and a touch unfair. Perhaps, in part, a byproduct of his inner need to theme every single puzzle (although this not a themed clue).