comma

Everyday

1. A comma is a punctuation mark (,) that shows a short pause or separates parts of a sentence. tree →
2. Commas separate things in a list: «eggs, milk and bread». tree →
3. In numbers, a comma groups digits in threes to make them easy to read: «1,000,000»; in many European countries a comma is used as the decimal point instead. tree →

In the lessons

In English lessons pupils use commas in lists, after a fronted adverbial («After lunch, we played»), around extra information («My brother, who is ten, plays chess»), before speech marks and in addresses. Phrases: «Oxford comma» or «serial comma» (a comma before «and» in a list), «comma splice» (two sentences joined only by a comma — a mistake). In maths, commas separate thousands in big numbers in the UK, USA and Australia, and coordinates are written with a comma: (3, 4).

Examples

• Put a comma between the items in a list. tree →
• «Let's eat, Grandma!» needs a comma, or it sounds like we are eating Grandma. tree →
• After a fronted adverbial, put a comma: «Later that day, it rained.» tree →
• My sister, who loves horses, rides every Saturday. tree →
• Write ten thousand as 10,000. tree →
• The point (2, 5) is two across and five up. tree →
• A comma shows the reader where to take a short breath. tree →

Note

Plural «commas». A comma is not a full stop: do not join two complete sentences with only a comma. In maths, «3,5» in France or Germany means three and a half, but in the UK and USA it is «3.5» — the comma and the decimal point swap between countries. Do not confuse «comma» with «coma» (a deep sleep after an illness or injury).