run on sentences
People learning French often notice something strange. Some sentences look wrong, because two complete thoughts sit on either side of a comma. There is no connecting word, no semicolon, no em dash — just a comma separating them.
In English, this is called a run on sentence, or a comma splice. It’s regarded as an error. In French, however, it’s often the right way to write.
The comma does more work in french
French trusts the comma to do things English does not. In English, a comma is a small pause that cannot hold two full sentences together by itself. You need a word like and or because (a conjunction) to do that work.
French lets the comma carry meaning. The connection between the two thoughts is understood and does not need to be spelled out.
Mon fils a de bonnes notes en français, c’est sa matière préférée.
“My son gets good grades in french, it is his favorite subject.”
Everyday french uses this all the time
In French novels, news websites or text messages from friends, you will see this pattern everywhere.
Il pleut, je ne sors pas.
“It is raining, I am not going out.”
Tu es fatigué, tu devrais dormir.
“You are tired, you should sleep.”
On a faim, on va manger.
“We are hungry, we are going to eat.”
Ça coûte trop cher, je ne l’achète pas.
“That costs too much, I am not buying it.”
Nous sommes en retard, le bus est parti sans nous.
“We are late, the bus left without us.”
Vous voulez du café, il y a une machine au fond.
“You want coffee, there is a machine in the back.”
Ils ont bien travaillé, ils méritent une pause.
“They worked well, they deserve a break.”
Elle prépare le dîner, elle met la table.
“She is making dinner, she is setting the table.”
The logic is often cause and effect
Most of these sentences work because one part explains the other. The comma stands in for words like because or so.
Il fait froid, je mets un manteau.
“It is cold, I am putting on a coat.”
Tu as raison, j’avais tort.
“You are right, I was wrong.”
On n’a plus de pain, il faut en acheter.
“We have no bread left, we need to buy some.”
Ça ne marche pas, je l’ai cassé.
“It does not work, I broke it.”
Nous sommes seuls, nous pouvons parler librement.
“We are alone, we can speak freely.”
Vous êtes prêts, on y va.
“You are ready, let us go.”
Ils ont gagné, ils sont contents.
“They won, they are happy.”
Sometimes the connection is different
Not every run on sentence shows cause and effect. Sometimes the second thought adds information, provides an example, or just keeps the sentence moving.
J’ai vu Pierre hier, il va bien.
“I saw Pierre yesterday, he is doing well.”
Tu connais ce restaurant, on y a mangé ensemble.
“You know that restaurant, we ate there together.”
On part en vacances demain, les bagages sont prêts.
“We leave on vacation tomorrow, the bags are ready.”
Ça sent bon ici, tu fais la cuisine.
“It smells good in here, you are cooking.”
Nous avons un problème, la voiture ne démarre pas.
“We have a problem, the car will not start.”
Vous avez reçu mon message, vous n’avez pas répondu.
“You received my message, you did not reply.”
Ils habitent à Lyon, c’est une belle ville.
“They live in Lyon, it is a beautiful city.”
Elle range sa chambre, elle veut faire plaisir à sa mère.
“She is cleaning her room, she wants to make her mother happy.”
Formal french does not allow this
The rules change when writing becomes formal. In a school essay, a government letter, or a job application, French acts more like English. Run on sentences become errors.
You would need to write properly.
Mon fils a de bonnes notes en français car c’est sa matière préférée.
“My son gets good grades in french because it is his favorite subject.”
Il pleut donc je ne sors pas.
“It is raining so I am not going out.”
Tu es fatigué, alors tu devrais dormir.
“You are tired, so you should sleep.”
The casual style works for most daily writing. The formal style is for places where people watch their words closely.
Other ways to connect thoughts in french
If you want to avoid the run on sentence in formal writing, you have choices. Each one changes the feeling slightly.
Using car for explaining
Il reste chez lui, car il est malade.
“He is staying home, because he is sick.”
Je prends ce livre, car il m’intéresse.
“I am taking this book, because it interests me.”
Using donc for result
Tu n’écoutes pas, donc je répète.
“You are not listening, so I am repeating.”
On a fini, donc on part.
“We have finished, so we are leaving.”
Using alors for consequence
Il pleut, alors on annule.
“It is raining, so we are canceling.”
Vous êtes là, alors on commence.
“You are here, so we are starting.”
Using et for adding
Elle cuisine, et elle écoute la radio.
“She is cooking, and she is listening to the radio.”
Ils dansent, et ils chantent.
“They are dancing, and they are singing.”
Using a semicolon for linking
Il fait beau; sortons.
“The weather is nice; let us go out.”
J’ai faim; je vais manger.
“I am hungry; I am going to eat.”
Using a colon for explaining
Il a réussi: il a beaucoup travaillé.
“He succeeded: he worked a lot.”
Je suis triste: mon chat est mort.
“I am sad: my cat died.”
When to use which style
The choice depends on where you are writing.
Use comma splices freely when
- writing to friends
- posting on social media
- keeping a personal journal
- writing dialogue in a story
- sending informal emails
Avoid comma splices when
- writing for school or university
- applying for a job
- sending official letters
- writing for a formal publication
- taking a language test
Summary
French allows comma splices in most daily writing. The comma alone can connect two complete thoughts. English requires a conjunction or different punctuation for the same job. The French style follows how people actually speak. Formal French bans this usage and follows the same rules as English. Knowing the difference helps you write appropriately for each situation.
