A comma is a punctuation mark that separates certain words within a sentence, such as in a list or group of words, or separates subordinate clauses and main clauses. Using commas carefully gives sentences their logical structure and makes reading easier by providing small pauses.

Example: “Let’s eat Grandma.”

Possible interpretations:

1. With the comma: You are inviting Grandma to eat.
2. Without the comma: You are suggesting that Grandma should be eaten.

In sentence parts with the same syntactic function, items are separated either by a conjunction or a comma.

Example with a conjunction: “We have a dog and a cat and a mouse and a bird.”

Example with commas: “We have a dog, a cat, a mouse and a bird.” or “We have a dog, a cat, a mouse, and a bird.”

Colons are also useful for introducing lists.

A comma is always placed between items in a list that are linked by conjunctions. With certain conjunctions and adverbs, a comma is always required.

Examples: “on the one hand, … on the other hand …”, “the more …, the more …”, “partly …, partly …”, “however,….”, “therefore,….”

However, if the words are considered equivalent, commas do not necessarily have to be used.

Examples: “and”, “or”, “as well as”, “both … and …”, “either … or …”, “neither … nor …”

Example: “You can decide either to go to the cinema tonight and watch the new movie you have been waiting such a long time to see, or you can stay at home, make yourself comfortable, and finally continue reading the book that has been lying on your bedside table for weeks.”

You can also combine independent and grammatically complete clauses – that is, main clauses – with commas.

Example: “She tore open the door. She screamed. She stumbled back.” becomes “She tore open the door, she screamed, she stumbled back.”

Punctuation can also be used to set off subordinate clauses.
Examples:

• “Peter knew that this could not work.”
• “Peter knew: This could not work.”
• “This could not work – Peter knew that.”

Examples: “because”, “when/if”, “while”, “after”, “although”

Appositions are explanatory additions and are either inserted into the sentence with commas or added afterwards.

Examples: “The dog, which barked loudly, ran across the field.” or “The dog ran across the field, it barked loudly.”

A comma separates comparative clauses from the main clause.

Examples: “She worked for as long as she had planned.” or “The report card was better than I had expected.”

If the part being compared is incomplete, the comma is omitted.

Examples: “I am just as fast as you.” or “The dog looks like a Labrador.”

An extended infinitive is the part of the sentence directly related to the “to + infinitive construction.”

Example: “It would be superficial to claim that all men are football fans.”

A comma is always necessary when the sentence would otherwise not be clear.

Example: “Uta tried not to sing the song.” Different: “Uta did not try to sing the song.”

The comma may be omitted if no misunderstandings arise while reading.

A participle is a verb form that lies between a verb and an adjective, and is usually followed by a comma. It does not matter whether it is a present participle or past participle.

Example: “Reading an exciting book, she did not notice that it had started to rain.” or “Having read an exciting book, she did not notice that it had started to rain.”

With equivalent adjectives that are used in a list, you use a comma. A fixed combination of a noun and an adjective that is further specified by another attribute is not separated by a comma.

Examples: “I have a preference for light, tart red wines.” or “I have a preference for dark Bavarian beer.”

Dates and times consisting of several parts and place names are separated by commas.

Examples: “She will arrive on Tuesday, March 20, at 2:00 p.m.” or “Nuremberg, September 9.”

The en dash primarily indicates a shift: a shift in expectation, topic, speaker, or sentence structure. It also creates a longer pause than a comma but a shorter one than a period.

Examples: “He thought he was safe – a fatal mistake.” or “This picture – the artist’s last – was sold to America a few years ago.”

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This article was published in August 2025 and last updated in November 2024.