This is what Americans would call a "Hail Mary" but...
From my notes on (then) Lieutenant or Rittmeister Anton Gundakar, Graf von Starhemberg of the Kavanagh Kuirassier regiment..
"during the siege and fall of Mantua, during the advance into the Riviera, during the occupation of the Papal States and Tuscany... probably served as an adc to his corps commander, the FML Baron Michael Fröhlich, on missions to the British Commodore Thomas Troubridge".
Troubridge was from very humble origins. Would he speak any foreign languages? I assume Starhemberg, an Austrian of Moravian descent, probably educated privately (no mention of his attendance at th Maria Theresa college) but maybe at a military school would speak German and as a gentleman French too, Italian also but at this point in history maybe not English? Troubridge went into the navy at an early age and would not probably have been exposed to much language tuition. How would they communicate? Perhaps a Neapolitan interpreter?
I am assuming the communication would be in code and require multiple interpreters.
K.
The language of command in the Austrian army was German, so Starhemberg would have spoken it and, as a noble, French. Rittmeister is a cavalry captain.
I saw Troubridge described thus: “He was zealous, fiery, honourable, resolute, brave beyond measure, dutiful, quick-tempered, excitable, moody, single-minded, direct, brusque and did not suffer fools gladly. In essence he was a true British bulldog. His language was as direct as his behaviour and as intemperate, and was rendered the more vigorous by his increasing deafness. His physical stature was impressive, he had a confident visage and a mature yet young looking face, and he spoke with an Irish influence in his accent.”
Despite his humble origins, he was educated at the famous London public school of St Paul’s, where entry was by competitive exam, albeit scholars did not have to pay fees. So, French was probably used, albeit through a hearing horn.