Commas to avoid ambiguity
Use commas to clarify meaning and avoid ambiguity in sentences where the absence of a comma could cause misreading
What a learner can do afterwards
- Insert a comma to prevent ambiguity, e.g. 'Let's eat, Grandma' vs 'Let's eat Grandma' or 'Most of the time, travellers worry about their bags'
- Identify sentences where a missing comma changes the meaning and explain the two possible readings
- Use commas after introductory elements (adverbial phrases, subordinate clauses) to prevent misreading of the main clause
1 · Read
Sometimes a missing comma changes who you are talking to, or even who gets eaten. One tiny comma can save a sentence from a very confusing meaning.
"Let's eat, Grandma" means you are inviting Grandma to eat. "Let's eat Grandma" means you want to eat Grandma. The comma is the only thing standing between a dinner invite and a monster movie.
Commas do this after introductory words too. "Most of the time, travellers worry about their bags" says travellers usually worry about bags. Without the comma, a reader might stumble and read "the time travellers" as one phrase, like time-travelling tourists.
When a sentence starts with a describing phrase or clause, add a comma before the main part. It tells the reader: this introduction is done, here comes the main idea.
A comma after an introduction, or before a name you're speaking to, stops readers from misreading your sentence.
More to read
Commas in complex sentences
A complex sentence has two parts. One part can stand alone as a full sentence. The other part cannot stand alone; it needs the first part to make sense.
When the part that cannot stand alone comes first, put a comma after it. The comma tells the reader: the opening idea is finished, and now the main part begins.
Example: Because of the strong winds, the plane could not take off.
Try reading it without the comma. Your eyes might stumble for a moment, because it is not clear where the first idea ends. The comma makes the sentence easy to read the first time.
When the part that cannot stand alone comes at the end, you usually do not need a comma.
Example: The plane could not take off because of the strong winds.
So remember this simple rule: opener first, add a comma. Opener last, no comma needed.
8.6 Editing Focus: Commas with Nonessential and Essential Information
A comma is a mark of separation. It tells the reader to take a tiny pause. Commas also help show which words in a sentence are extra and which words are needed.
Extra information is a detail you could remove and the sentence would still make sense. We wrap extra information in commas, like this: My brother, the one with red hair, plays soccer. You could take out the words between the commas and the sentence still works.
Needed information cannot be removed, because taking it out would change the meaning or confuse the reader. Look at this pair:
The students who studied passed the test. (Only the students who studied passed. These words are needed, so no commas.)
The students, who studied, passed the test. (All the students passed, and by the way, they studied. The commas make it extra info.)
See how commas can change what a sentence means? When you write, ask yourself: is this detail needed to understand the sentence, or is it a bonus? Then add commas only around the bonus parts. That way your reader always knows exactly what you mean.
2 · Watch
En anglaisTake it off screen
Where it sits
Learn first
Optional connections
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Nothing builds on it yet.
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
24 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.