Grammar

Punctuation in written forms of speech

Addressing someone
In conversation, you often mention the name of the person you are talking to. This form of addressing someone by name is separated from the rest of the sentence by a comma. That can be at the beginning or end of the sentence or clause.

Examples:
Anna, was machen wir jetzt?
Worüber denkst du nach, Harry?
Gut, Anna, wir werden einen Plan machen.

In letters, too, the name of the person you are addressing is followed by a comma and the rest of the sentence is written without a capital letter at the beginning. To express particular emphasis in the greeting, you can use an exclamation point instead of a comma. The words that follow form a new sentence and therefore must begin with a capital letter.

Examples:    
Sehr geehrter Herr Walkott,
wir laden Sie zu einem Vortrag über die Zeitschleife ein.
    Lieber Harry!
Wie geht es dir?

 

Exclamations
Exclamations, commentary and affirmations in sentences are also separated by a comma.

Examples:
Ja, wir haben Spaß.
Ah, genau, der Banküberfall!
Okay, also hier ist der Eingang der Bank.

Additions and afterthoughts
Additions and afterthoughts can be inserted into sentences to emphasize or provide more information about certain words or groups of words. Such additions are separated by commas and appear next to the word(s) they refer to.

Examples:
Wir treffen uns dort, vor der Bank.
(The afterthought "vor der Bank" provides more information about the intended meaning of "dort".)

The insertion is also closed off by a comma if the sentences continues afterwards.

Example:
Wir treffen uns dort, vor der Bank, und gehen gemeinsam hinein.

If a word refers to a previous word or group of words, then it is separated by a single comma.

Example:
Du und dein Kollege Helmut, ihr seid zur Bank gefahren.
(The pronoun "ihr" provides particular emphasis by referring back to the phrase "Du und dein Kollege Helmut".)