YOU SAID:
His Royal Highness has arrived at the aeroport.
INTO JAPANESE
彼の殿下は航空港に到着しました。
BACK INTO ENGLISH
His Highness has arrived at the airport.
INTO JAPANESE
彼の殿下が空港に到着しました。
BACK INTO ENGLISH
His Highness has arrived at the airport.
You should move to Japan!