Many comma rules in German are different from and arguably stricter than in English. In this post, I explain when to put a comma and when not use one.
Commas in German are chiefly used to separate main from subordinate clauses. Bear in mind that the difference between the two types of clauses is also reflected by word order in German. While the conjugated verb is in second position in a main clause, it goes to the end of the subordinate clause.
MAIN CLAUSE SUBORDINATE CLAUSE
Ich weiß, dass ich Vokabeln lernen muss.
(I know I need to learn vocabulary)
Sie will Deutsch lernen, weil sie einen Deutschen Mann hat.
(She wants to learn German because she has a German husband)
German relative clauses are special type of subordinate clause that are used to provide further information about a noun. Accordingly, they follow the same rule and are separated from the main clause.
MAIN CLAUSE RELATIVE CLAUSE MAIN CLAUSE
Der Mann, der aus Deutschland kommt, heißt Paul.
(The man, who comes from Germany, is called Paul)
Die Katze, die auf dem Sofa liegt, schläft friedlich
(The cat, who is lying on the sofa, is sleeping peacefully)
Commas are also used between complete main clauses, unless they are joined with und, sowie, beziehungsweise, sowie, wie and the so-called compound conjunctions entweder....oder, weder....noch, sowohl...als. There is no such thing as the serial comma, also known as ‘Oxford comma’ in German. So you never need a comma before und in German.
Sie kaufen normalerweise Eier, Brot und Milch
(They normally buy eggs, bread, and milk)
Er geht immer zu Fuß zur Arbeit und er fährt mir den Bus in die Stadt
(He always walks to work, and he takes the bus to town)
Like in English, commas divide units and statements belonging to the same category and appositions. Again, with the exception of the Oxford comma.
Im Urlaub wollen wir lange schlafen, gut essen und uns richtig erholen
(On holiday, we want to have a lie in, eat well, and properly relax)
Die Themse, der zweitlängste Fluss in Großbritannien, fließt durch London
(The Thames, the UK‘s second largest river, flows through London.
Last but not least, there is one situation where the comma is optional nowadays because punctuation rules were changed in the past. In infinitive clauses, you may use a comma but not is not incorrect if you don't.
Sie hoffen, ihr Deutsch schnell zu verbessern.
(They hope to improve their German quickly)
Plant ihr, am Wochenende auszugehen?
(Do you plan to go out at the weekend?)
Check out our German grammar explanations on our blog "Auf Deutsch, bitte!" We explain, for example, how to use the articles in German, the dual prepositions in German, and how to use je...desto/umso.