Learn Hardcore French: Auparavant, je mettais du beurre de cacahuète; maintenant, je préfère la confiture. - Previously, I used to put peanut butter; now, I prefer jam.

If you said j’ai mis du beurre de cacahuète, it would mean “I put peanut butter (on one particular occasion / at a specific moment).” That would not match the idea of a past habit that has now changed.

Could I say Avant, je mettais du beurre de cacahuète instead of Auparavant? What is the difference?

Yes, you can say:

Avant, je mettais du beurre de cacahuète; maintenant, je préfère la confiture.

The difference:

Avant is very common and neutral.
Auparavant is a bit more formal or literary and often used in writing or storytelling.

In everyday spoken French, avant is more frequent; in written French (especially narrative), auparavant sounds slightly more elegant or “bookish.” Both are correct here.

Why is there a comma after Auparavant?

When an adverbial phrase or word like Auparavant, Hier, Ce matin, Normalement, etc. comes at the beginning of the sentence, French often uses a comma:

Auparavant, je mettais…
Hier, je suis sorti…

The comma marks a little pause and separates the time phrase from the main clause. It is not absolutely mandatory, but it is very standard and recommended.

What exactly does du mean in du beurre de cacahuète?

Du = de + le and is a partitive article.

It is used with mass nouns (things you don’t usually count: butter, water, rice, etc.) to mean “some” or “an unspecified amount of.”

du beurre = “some butter”
du beurre de cacahuète = “some peanut butter”

You use du / de la / de l’ when you are talking about an unspecified quantity of a non-count substance, not about butter in general as an abstract category.

Why is it du beurre de cacahuète and not le beurre de cacahuète?

du beurre de cacahuète = “some peanut butter” (what you put on your bread)
le beurre de cacahuète = “peanut butter” as a general concept or a specific, known peanut butter

Here the speaker is talking about what they used to put on something (toast, bread, etc.), i.e. some quantity used in practice, so the partitive du is natural.

If you were making a general statement, you might use le:

Le beurre de cacahuète est populaire aux États-Unis.
“Peanut butter is popular in the United States.”

Why is it la confiture and not de la confiture after je préfère?

With verbs of preference (aimer, préférer, adorer, détester), French normally uses the definite article (le, la, les) to talk about things in general:

Je préfère la confiture.
“I prefer jam (in general).”
J’adore le chocolat.
Elle déteste les oignons.

De la confiture would emphasize “some jam” as a quantity, but after préférer, that sounds strange. Preferences are typically about categories, so you use le / la / les, not du / de la / des.

Why do we repeat je in maintenant, je préfère la confiture instead of just saying maintenant, préfère la confiture?

In French, you normally must use an explicit subject pronoun (je, tu, il, etc.) with the verb. French is not a “null-subject” language like Spanish or Italian.

So you say:

Maintenant, je préfère la confiture. ✅
not
Maintenant, préfère la confiture. ❌

Each clause needs its own subject pronoun, even if it’s the same subject as in the previous clause.

Is the semicolon (;) used in French the same way as in English? Could I use a period instead?

Yes, the semicolon in French is broadly similar to English:

It links two closely related clauses that could be separate sentences.
It shows a stronger break than a comma but a closer link than a period.

Your sentence could also be written as two separate sentences:

Auparavant, je mettais du beurre de cacahuète. Maintenant, je préfère la confiture.

That is perfectly correct and perhaps more common in everyday writing.
A comma alone (without coordinating conjunction) would be less formal and sometimes seen as a run-on:

Auparavant, je mettais du beurre de cacahuète, maintenant, je préfère la confiture. (often seen, but stylistically weaker)

Is beurre de cacahuète the only way to say “peanut butter” in French?

No, there are variants:

beurre de cacahuète – common, especially in France (influenced by English “peanut”)
beurre d’arachide – common in Canada and some other regions (from arachide = peanut)

Both are understood. Choice depends on region and personal habit. Grammatically they work the same way:

Je mettais du beurre d’arachide.

Why is it beurre de cacahuète and not something like beurre aux cacahuètes?

The structure noun + de + noun is very common in French to express composition:

beurre de cacahuète = butter made from peanuts
jus d’orange = orange juice
soupe de tomate = tomato soup

Aux (à + les) is more often used when something is served or cooked with something, or containing pieces of it:

poulet aux champignons = chicken with mushrooms
tarte aux pommes = apple tart (with pieces of apple)

Peanut butter is essentially “butter from peanuts,” so de is the natural choice.

Why is confiture singular and with la? In English we say “jam” as a mass noun; is it the same?

Yes, it’s similar:

la confiture can be used the way English uses “jam” when you mean jam in general.
Je préfère la confiture. = “I prefer jam.”

If you were talking about servings or types, you might have plurals:

des confitures maison = homemade jams
J’ai goûté plusieurs confitures. = I tasted several jams

But for a general preference, la confiture (singular, with la) is standard.

Could I replace maintenant with désormais or à présent?

Yes, but there are nuances:

maintenant – neutral, very common in speech and writing, “now, at present.”
à présent – similar to maintenant, but can sound slightly more formal or stylistic.
désormais – means “from now on, from this point onwards”; it emphasizes a change with an idea of “from this time forward.”

So:

Auparavant, je mettais du beurre de cacahuète; désormais, je préfère la confiture.

This version underlines the idea that things have changed and that from now on the new habit will continue. It is a bit more formal than maintenant.

How is mettais pronounced, and why is it written with -ais?

Mettais is pronounced roughly like [me-tɛ] (two syllables, final -s silent).

It is the imperfect form of mettre for je and tu:

je mettais, tu mettais – both pronounced [mɛtɛ]

The -ais ending is the regular imperfect ending for je and tu in most verbs:

je parlais, tu parlais
je finissais, tu finissais

So mettais follows the normal spelling pattern of the imperfect, even though the pronunciation is the same as the present je mets ([mɛ]).

Does auparavant refer to any particular past time, or is it vague?

Auparavant is intentionally vague about the time. It just means “earlier / previously / before that,” without saying when exactly.

The sentence contrasts two periods:

before (at some earlier period): Auparavant, je mettais du beurre de cacahuète
now: maintenant, je préfère la confiture

If you wanted a more precise time, you would replace auparavant with something like avant l’année dernière, quand j’étais enfant, etc.