Surprisingly Good Foreign Language

Truth #1: Foreign languages sound more exotic. Buying some body lotion is not the same as buying La Creme Luxueuse, and driving a car is not the same as driving a Motorwagen.

Truth #2: Unfortunately, not many people are fluent in foreign languages.

Truth #3: But sometimes, they are.

Horrible grammar and pronunciation of any foreign language is the expected norm in most works of fiction. Even if you do manage to get the grammar right (harder than it sounds), unless you either have an actor who is a native speaker or a very good language coach to help them, their accent is going to be blatantly obvious, and oftentimes won't even register to native speakers as the language in question.

But if you can get the grammar and the accent right, viewers will be pleasantly surprised. This allows for a number of other language tropes, such as Bilingual Dialogue and Bilingual Bonus.

Surprisingly Good English is an English-specific subtrope.

When a character is surprisingly good at understanding a language that others are speaking, that's a Bilingual Backfire.

Examples of Surprisingly Good Foreign Language include:

Anime and Manga

So Ra No Wo To:. Minor character Aisha speaks excellent Roman.
The Nodame Cantabile second season's ending is sung in perfect, unaccented French (this troper heavily suspects they contracted natives to write and sing it).^{[please verify]}
Wolf's Rain has Surprisingly Good Russian. The announcement on the railway station is spoken in flawless Russian, without any accent.
One of the ending themes in Tsukuyomi Moon Phase is sung in Surprisingly Good French!
Gosick is choke-full of perfectly-written French, including accented character and adequate idiotisms. The English parts of the ending are also very well pronounced.

Film

Slap Shot: The two French-Canadian characters are played by French-Canadian actors; thus, they speak both French and English like French-Canadians would.
In X-Men: First Class, Magneto and the Nazis he encounters (and, a bit later, kills) in the bar, speak surprisingly good German. The actor playing Magneto was born in Germany and the actors playing the Nazis are most likely German.
The Good, the Bad, the Weird, a Korean remake of The Good, the Bad and the Ugly IN 1930s MANCHURIA!, features (as one would expect from the setting), a lot of Mandarin and Japanese, as well as Korean (the three central characters are all Korean exiles). The Mandarin and Japanese are surprisingly good.

Live-Action TV

On Charmed, Cole speaks very good Italian.
Whose Line Is It Anyway?: The game Foreign Film Dub with guest star Sid Caesar.
Flight of the Conchords: When Bret performs a Korean Karaoke song, both on the HBO show and on stage, his pronunciation is unexpectedly good.
Stargate Atlantis: The episode Duet features two startingly flawless lines in German from an extra. (There are no subtitles. The lines translate to "Ew, this is like the birth of my nephew." and "Damn, I knew this was going to happen!" respectively.) This is because the lines were ad-libbed and the actress was born in Germany. David Nykl, who personally translated some of Dr. Zelenka's lines into Czech, ad-libbed some swearing, and otherwise puts on a fairly good Czech accent for the role, also has Czech parents and spent some years in the country as a baby and as an adult.

Music

If you didn't know that salsa band Orquesta de la Luz was from Japan, you could never tell by the excellent Spanish they sing. And even if you do know, it's still hard to tell.
The Swedish Heavy Mithril band Dragonland did a cover of X Japan's song "Rusty Nail", and the vocalist's Japanese skill has to be heard to be believed. This troper, who wasn't familiar with the band prior to hearing this cover, actually assumed they were Japanese until he looked it up on Wikipedia.

Video Games

Inverted in Saints Row 2 with Ronin leaders Shogo and Kazuo Akuji and The Dragon Jyunichi, who each speak Surprisingly Good Japanese.

Western Animation

My Life as a Teenage Robot has one episode with Surprisingly Good Japanese. After a mission in Tokyo, Jenny loses her English-language disc, and can only speak Japanese for the rest of the episode. Her voice actress, Janice Kawaye, is bilingual and her lines are absolutely flawless.