"He is fine."
you can, you can also say 'yeye ni sawa' they all mean the same thing. Swahili was my first language and I'm forgetting and its kinda annoying being told that I am wrong when I know that I aint
Though depending on context - I would have translated "Yeye ni mzuri." as "He is good/beautiful." - it is less common (in what I have heard).
As far as I understand (I've studied Swahili in a class for a few years), the English translation is a bit odd. So "yeye ni mzuri" is technically correct for "he is fine," but "hajambo" is more of a greeting, and you would never say "yeye ni mzuri" if the question asked was "Hajambo?" Words ending in jambo function as both a question and a response.
"Ha" is a third-person singular signifier, just like how "si" is first person singular and "hu" is second person singular, so "hujambo" is "how are you" and "sijambo" is "I am fine."
I am unclear on the reason why 'yeye hajambo' would not be accepted if anyone could help.
Report it - it is fine; putting "yeye" in front is stressing "him" - similar to French "je" and adding "moi" at the beginning.
It all depends on the punctuation mark. With a questionmark it is a question. With a dot it's the affirmation.
I responded with 'Ako salama'. I believe that should be an acceptable answer as well.