From Hyde Flippo,
Your Guide to German Language.
When to use the three German 'you' words
How to say "you" in German
Even English-speakers who think they know German well can fail to grasp the true significance of the two forms of "you" in German, Sie and du/ihr. There's an old joke about the translation problem: "Let's be on familiar terms. You can just call me 'you.'" (OK, it's not that funny unless you're really into translating or cultural linguistics.)
Part of the problem is the death of "thou" and the plural form of you (ye) in English. (In the southern U.S. "y'all" fills in for "ye" - which later became singular.) English, with its one and only "you" for everyone and every degree of formality or informality, stands pretty much alone in the way it deals with "you." Except for English, all the Indo-European languages, including German, have both a formal "you" and a familiar "you." For some reason the familiar "thou" (and its "thee," "thine," and "thy" forms) died out in English but not in most other languages.
In modern English we only run across "thou" in the Bible, Shakespeare, or in Quaker country. (For an interesting look at "thou" in English see Alan Firth's Linguist List "Thou and You" summary from the Quakers.)
The German familiar term du is actually related to "thou." This is more apparent once you become aware of the so-called "d<-->t/th shift" between German and English, seen in many word pairs such as Leder / leather and rot/red. (This fact is very useful in guessing the meaning of certain German cognates, or words similar to English. See more below.)Free Quote
The real problem isn't just grammar; it is also a matter of culture. An English-speaker is not used to making the distinction between the familiar and formal you (except in the similar "Mr. Brown" vs. "Bob" situation). German-speakers are very much aware of it and can become very uncomfortable when the du/Sie rules are broken. German-speakers tend to keep their distance longer with acquaintances than English-speakers do. German business colleagues who have worked together for years continue to address each other as Sie. It does not mean they are unfriendly, but they are maintaining the important German division between truly close friends and mere acquaintances.
So what are the rules? Every beginning German student learns that you use Sie for formal address (Wie heißen Sie? - What is your name?) and du (plural, ihr) for the familiar (Hans, hast du deinen Mantel? - Hans, do you have your coat?). Sie is for strangers or people you don't know well. Only God, children, pets, close friends, and family members are addressed as du.
But things can get more complicated than that, even for Germans. For instance, what if you're being introduced to the German in-laws you've never met before? Should you use Sie or du? They're strangers but they're also family. The standard rule—and it's a good one—says always use Sie when in doubt. But your relatives might be offended by your stiff formality in this case. Using Sie when du is called for, can even convey anger or displeasure! But du used when Sie is appropriate can sound condescending - even insulting! ...Hilfe! Help! (See Part 2 for tips.)
Then there's the neue Rechtschreibung spelling reform that says you should no longer capitalize du or ihr in a letter. Yet many Germans continue to do so... either out of habit or stubbornness.
Below we have listed some helpful guidelines. (For more see the Friends and acquaintances chapter of The German Way.)
Before you take the quiz, review these tips...
When to use Sie, du or ihr
Use the formal Sie form when...
you are talking to adults you only know casually or have just met.
the situation would call for using "Mr." (Herr) or "Ms./Mrs." (Frau) in English. (Caution! See below about using first names.)
in a business situation unless specifically invited to do otherwise.
addressing colleagues at work (unless they are close friends of yours).
you have doubts about which form to use.
Use the du form when...
talking to family members or relatives.
talking with close, intimate friends.
addressing children under the age of about 12 and pet animals.
addressing God, as in a prayer.
you are invited by the German-speaker to do so.
NEXT > In Part 2 we take a closer look at du and Sie and offer a Self-scoring Quiz to test whether YOU understand "you" in German!
Some Common German/English Cognates
With consonant shifts