This is in response to Haru's question: http://www.italki.com/question/232471. I think others might be able to benefit from this, too.

So, here is my loooooooong explanation and analysis! If you want the short version, it's here:
"Those words are fit for a queen!"
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Here's the long version:
The other users have noted that the speech they use in "Jeeves and Wooster" sounds old and outdated; that is why it sounds strange even to our ears (especially to those speaking American English like me).

Here's what I think:

First, we have to understand that the TV show involves some humorous dialogue, in order to be entertaining. So their dialogue is more theatrical, staged, or scripted. I think that is what we have in this instance here.

So, in the car, before they step out, Jeeves first says "With Miss Wickham, sir?"
We can tell from his tone of voice and by Bertie's response that Jeeves is not really asking "Are you in love with Miss Wickham?" but really "Why would you be in love with a person like Miss Wickham?"

Bertie then says, "No need to say it like that," and later asks "Just what exactly is your kick against Miss Wickham?" I think I have to translate this to understand it myself! I think he means "Just what exactly do you have against Miss Wickham?"

Then, Jeeves starts a sentence, saying "Well, sir, although Miss Wickham is a very charming young lady--"

And then here's another bit of humor, which you have to take into context.
Jeeves hasn't even finished his sentence yet, and is saying "...although Miss Wickham is a very charming young lady"--so we know that he is about to say something contrary to "charming."
例えば、「優しいことは優しいですけれど。。。」Indeed, later we see that he calls her "frivolous," and says that "Whenever l see Miss Wickham, l know that trouble cannot be far behind."

BUT!
Before Jeeves has a chance to say any of that, Bertie interrupts him. The way he responds is where the humor is. Jeeves says "although", which means he is about to say something contrary to "charming," but Bertie responds saying "Exactly! You speak an imperial court!"

So really, Bertie is not saying 「そうですよね！優しいことは優しいですけれど、Wickhamさんとの付き合いのは面倒なことになるのですね！」or "Exactly! She may be charming, but she's always close to trouble!" He's saying 「そうですね！優しい人ですね！」or "Exactly! She is charming, isn't she!"　And that isn't at all what Jeeves was saying, which is what is sort of humorous.

So, that is the context. What about the sentence itself?

I think I understand "You speak an imperial court!" to mean "You speak [like] an imperial court!" or "You speak [as if you were a part of] an imperial court!"

And I think in context, that line means "I think that the word you used to describe Miss Wickham was fit for a queen!" or "I think that the word you used to describe Miss Wickham was good enough to be used by the imperial court to describe somebody with as high a position as the emperor (or empress) of a country!"

And the humor is that all that Jeeves says is "very charming," which doesn't sound fit for a queen at all, but Bertie goes on to praise Miss Wickham as if he weren't really even listening to Jeeves.

And that's all. I think it's interesting to see how much meaning a simple sentence can carry in a certain context. I almost agreed with Jura, that the sentence didn't make sense, but when I saw the origin of the quote, I began to understand what it meant. So, what's hard for you is hard for us native speakers, too!

If you practice enough, you can get there! Keep it up! (^_^)