One HoTD Character's High Valyrian is Surprisingly Bad
You thought all characters in House of the Dragon could casually speak High Valyrian? Turns out, nope.
High Valyrian is a language that comes from the old Valyrian Freehold which was located on the eastern continent of Essos. This language is also used by dragonriders for communication with their winged beasts, but not every Targaryen (or Velaryon) is able to speak it fluently.
The characters who use it in the show the most are Daemon Targaryen (Matt Smith ) and young Rhaenyra Targaryen (Milly Alcock). But one actor, according to an HBO making-of clip posted on Instagram, basically had to pretend his character perfectly understands what is going on when somebody speaks High Valyrian.
It was Steve Toussaint, who portrayed Lord Corlys Velaryon. The actor admitted that he had to learn to "pretend" he understood everything.
Other actors also assessed their own levels of High Valyrian, with Emma D'Arcy (older Rhaenyra) saying that she has a "traveller's" level of High Valyrian and "could maybe order a beer". Matt Smith, naturally, boasted his character's fluency in the language, while Paddy Considine revealed how to say "Can I please excuse myself and go to the toilet, miss?" — apparently showing off his own impressive knowledge of High Valyrian.
High Valyrian does not sound in House of the Dragon very often, with the beginning of the show featuring a couple of lines in this language, but the later episodes only having separate people occasionally dropping a word or two — usually to their dragons.
Maybe we'll get to hear more of the language in the second season of the Game of Thrones prequel, which is due to start filming in early 2023. The premiere date will be announced later.