Il se peut que nous mangions de la soupe aux pommes de terre ce soir, à moins que Marie préfère les épinards avec du riz.

Il se peut que is a fixed impersonal expression meaning it may be that or it is possible that.

A few useful points:

• Il here does not refer to a person or thing. It is just an impersonal it, like in it is raining.
• se peut comes from se pouvoir, an old-style expression that survives mainly in this phrase.
• The whole chunk Il se peut que... introduces uncertainty or possibility.

So learners should usually treat Il se peut que as one set expression.

Because que introduces the next clause: que nous mangions...

French often uses que after expressions that introduce another idea, especially after:

• feelings
• doubt
• possibility
• necessity
• judgment

Here, Il se peut que is followed by a whole clause, so que is required.

Structure:

• Il se peut que
  • clause

So:

• Il se peut que nous mangions...
• literally: It may be that we eat...

Because Il se peut que requires the subjunctive, and mangions is the present subjunctive form of manger for nous.

Compare:

• Indicative present: nous mangeons
• Present subjunctive: que nous mangions

This is one of the most important things to notice in the sentence:

• Il se peut que expresses possibility
• after that, French uses the subjunctive

Also, the spelling changes naturally:

• mangeons has eons
• mangions has ions

The g still keeps the soft sound because it comes before i in -ions.

You know from the grammar trigger.

After Il se peut que, French normally uses the subjunctive, so mangions must be understood as subjunctive here.

It is true that nous mangions is also the imperfect form of manger, and the spelling is identical. But in this sentence, the context makes the meaning clear:

• Il se peut que calls for the subjunctive
• ce soir points to a present/future situation, not a past one

So here it means something like:

• we may eat not
• we were eating

Because after expressions like Il se peut que, French often uses the present subjunctive even when the action is in the future.

The time is shown by the context:

• ce soir = tonight

So French does not need a future form here. The idea is:

• It may be that we eat potato soup tonight

This is very normal in French:

• present subjunctive after a trigger
• future meaning supplied by context

À moins que means unless.

It introduces an exception:

• maybe we will eat potato soup tonight
• unless Marie prefers spinach with rice

It is a very common conjunction, and it is important because it also normally requires the subjunctive in the clause that follows.

So the pattern is:

• à moins que
  • subjunctive

That is why the sentence has:

• à moins que Marie préfère...

Yes. After à moins que, French normally uses the subjunctive, and préfère here is subjunctive.

What makes this confusing is that for many verbs, some subjunctive forms look exactly like the present indicative forms.

For préférer:

• indicative: Marie préfère
• subjunctive: que Marie préfère

So the form looks the same, but the grammar is different. The conjunction à moins que tells you that this is subjunctive.

Good question. In more formal or traditional French, you often see:

• à moins que Marie ne préfère les épinards...

This ne is called explétif ne. It does not make the sentence negative.

So:

• à moins que Marie préfère... and
• à moins que Marie ne préfère...

mean the same thing here.

In modern everyday French, especially in speech and less formal writing, the ne is often omitted.

These articles reflect how French treats each noun.

• de la soupe: partitive article, meaning some soup
• du riz: partitive article, meaning some rice
• les épinards: definite article, literally the spinach

Why les épinards?

In French, épinards is very often used in the plural when talking about the dish or ingredient in a general way. So les épinards is the normal form in many contexts.

So the sentence is not inconsistent; it is just following normal French usage with food nouns.

In names of dishes, French often uses à / au / aux to indicate a main ingredient or style of preparation.

So:

• soupe aux pommes de terre = potato soup
• literally, something like soup with potatoes

Here:

• aux = à + les
• because pommes de terre is plural

You will often see this pattern in food vocabulary:

• tarte aux pommes
• glace au chocolat
• omelette aux champignons

So soupe aux pommes de terre is a very natural food expression.

Pommes de terre is the normal French word for potatoes.

Literally, it means apples of the earth or earth apples, but learners should treat it as a fixed expression meaning potatoes.

A few things to notice:

• singular: une pomme de terre = a potato
• plural: des pommes de terre = potatoes

In the sentence, it is plural because the soup is made with potatoes in general, not just one potato.

French often places time expressions like ce soir, demain, or ce matin after the verb phrase, especially in neutral word order.

So:

• Il se peut que nous mangions de la soupe aux pommes de terre ce soir

sounds completely natural.

You could also move ce soir for emphasis in some contexts, but the version in the sentence is the most straightforward and idiomatic.

Yes, in everyday spoken French, many speakers would naturally say on instead of nous:

• Il se peut qu’on mange de la soupe aux pommes de terre ce soir...

That sounds more conversational.

The version with nous is still perfectly correct and common, especially in writing or in slightly more careful speech. So this sentence is natural, just a bit more standard in tone than very casual spoken French.