“Es heißt "für wen", nicht "für wer".”
“Das Komma befindet sich zwischen den umschließenden Anführungszeichen und es sollten einfache statt doppelte Anführungszeichen verwendet werden.”
Grammar Nazis are people (or cats) who use their freakishly and/or annoyingly powerful understanding of and compliance with grammar and spelling to attempt to "correct" others, usually the blissfully-oblivious-to-the-outside-world members and users of the Internet, who only understand the grammatically genocidal text-speak. However, the Grammar Nazi sees "correcting" others as "making" others "look like fools", and the others in question see the Grammar Nazi as "some asshole with no life." Today, most Grammar Nazis have settled down from the violent battles of "
der gut ölde days Die guten alten Tagen" (Entweder schriebt ihr Deutsch oder Englisch ihr verdammte Idioten!) to shadowy lives of correcting the error-ridden comments found below.
The Ever History
Of all the things that started when the internet was created, the Grammar Nazis are the worst. They all said, "Hey, we are better with English than you, so we are all going to start correcting you more often." They then started making concentration camps for people to go to so that they may concentrate on their spelling, grammar, and punctuation. The first concentration camps were a place where one is sent. The Grammar SS make one read books, and if one does not read the books properly (or one cannot read), the Grammar SS says to the person, "You are going for a shower", and they gas the person. 6 million trolls were gassed in the Grammar Holocaust. Hitler and his Grammar Nazis almost had the world under their control. They only stopped because they could not take over Britain, thanks to Winston Churchill, Dangermouse, Superman, and the people from London who could spell better than the Nazis.
The Apostrophy~Phrasengarian Empire
The Apostrophy-Phrasengarian empire was the product of years of hard-work by the apostrophe to do just about anything. It began by simply taking over letters such as in the phrase "I am," where the apostrophe army completely wiped out the "A" armies' defenses. 
In 1914, however, Arch-Duchess Fronts Further-and was assassinated by an enraged plural possessive. This was due to its resentment at often being left out and replaced by the inferior singular plural, or even omitted altogether. This resulted in the first Word War, fought entirely for the sake of language. While the British could easily decipher the inflection and apostrophe-free language of the Germans, the Germans found it difficult to fathom the wider British vocabulary and more complex use of apostrophes. 
One of the biggest proponents against the Apostrophy-Phrasengarian empire was Adolf Hitler who mobilised his forces against them. While the English were happy to appease the tyrant, the Academy Française would not allow it and insisted that Britain join it against the young Hitler, whose language was known to be rhetoric and devoid of grammatical structure. 
Rise of the Third Write
bye (Falsche Rechtsschreibung!) By the end of 1918, (mit (WELCHER DUMMKOPF SCHRIEB 'WIT'?) einem Komma, Dummkopf!) germany (Großschreibung, Idioten!!) Germany had exhausted its supply of scrabble sets. America soon entered the war. Due to their endless supply of Mark Twain novels and outlandish accents, the Axis Powers were forced to surrender.
The inter-war years were hard for Germany. The country had been forced by France to adopt 1337 speak in all of its official correspondence. Anarchy reigned, and a good German found it increasingly hard to find a decent Bratwurst. 
Embittered by his country's defeat and poor grammar, Adolf Hitler formed the Nazi Party. Soon, millions flocked to his call'n' es to thear his speeches on the proper use of "its" versus "it is".
In 1933, Hitler rose to power on a platform of improved literacy programmes and the banning of democracy. Soon the world began to tremble before the might of his grammatical knowledge and boots. 
In 1938, Hitler returned in triumph to Vienna. In a process known as "Anschließen" (German for fucking a bad idea), Austria united with Germany. In 1939, Hitler demanded that Poland and Czechoslovakia get rid of all those dots (ü) above their letters. The allies refused and the world was plunged into war. 
Word War II
At first, the squadron superior Lexicon and Grammar led them to overrun Eastern Europe and France, but hey, this is the French we're talking about. You just
has have to throw a moldy onion or two at them and they start dropping their guns; or politely ask them to surrender and they'll do it.
However, Britain managed to hold out against the power of the Grammar Nazi Empire thanks to the rhetoric of Winston Churchill. Japanese planes were
freinds friends allied with the Grammar Nazis, and due to this they sent some bombs to Hawaii to piss off America. For some reason, America entered the war. The Germans could not hold out against the American policy of 'General Ignorance.' Thus ended Hitler's dreams.
How to react
Many people think that a Grammar
Nazis Nazi's weakness is seeing a lot of grammatical errors. If you encounter a Grammar Nazi, then do not quickly make a lot of grammar grammatical errors. It simply makes them angrier. Instead:
- Remind them that you have a significant other, and have had sex more times
thenthan they have read The Elements of Style. Try to keep a straight face.
- Attack them with insane amounts of chatspeak. No Grammar Nazi can stand a chatspeak-barrage for very long,
Uunless said Nazi speaks chatspeak himself.
- In the rare case that the Grammar Nazi does speak chatspeak, run like hell.
- Screw with them by using loose interpretations of "effect". For example, say "the government has effected major changes," and when they get all douche-baggy and tell you it is "affect," find a dictionary and show them that they are wrong. (Real Grammar Nazis would not need to find a dictionary.)
- Bait them into a confrontation by spelling "whiny" as "whiney". When they try to correct you, show them that "whiney" is also an acceptable spelling, and enjoy your small victory.
- Tell them that being a Grammar Nazi is the difference between knowing your crap, and knowing you're crap.
- Comfort them by saying "Their, There, They're."
- It's "for whom", not "for who".
- The comma goes inside the closing quotation marks and single-quotes should be used instead of double-quotes.