Learn Hardcore French: Nous ne voulons pas gaspiller de nourriture, alors nous gardons les restes pour le lendemain. - We do not want to waste food, so we keep the leftovers for the next day.

In an affirmative sentence you’d normally say:
- Nous voulons gaspiller de la nourriture. → We want to waste (some) food.
After ne … pas, the partitive article de la / du / des usually becomes just de:
- Nous ne voulons pas gaspiller de nourriture. → We don’t want to waste any food.

So:

de nourriture = “any food / food (in general)”
la nourriture = the food (specific, all of it)
des nourritures is almost never used in everyday French; nourriture is usually uncountable.

Why do we need both ne and pas for the negation?

Standard written French negation uses two parts around the conjugated verb:

ne
- conjugated verb + pas
  → nous ne voulons pas (we do not want)

In everyday spoken French, people often drop ne and just say:

On veut pas gaspiller de nourriture.

But in correct written French (and in careful speech), you keep ne … pas.

Why is pas placed after voulons and not right before gaspiller?

Negation in French wraps around the conjugated verb, not the infinitive:

Conjugated verb: voulons
Infinitive: gaspiller

Structure:

nous ne Voulons pas gaspiller
not
~~nous ne voulons gaspiller pas~~

So the frame is: ne + [conjugated verb] + pas + [infinitive].

What tense are voulons and gardons, and why the present tense?

Both voulons and gardons are in the present tense, indicative mood, 1st person plural (nous).

nous voulons = we want
nous gardons = we keep / we are keeping

French often uses the present where English might use:

simple present: we don’t want to waste food, so we keep the leftovers
or even a habitual meaning: we never want to waste food, so (as a rule) we keep leftovers

The French present can express both “right now” and “as a general habit,” depending on context.

What exactly does gaspiller mean, and how is it different from perdre or dépenser?

Gaspiller means to waste, in the sense of using something badly or letting it go to waste:

gaspiller de la nourriture = to waste food
gaspiller de l’argent = to waste money
gaspiller de l’eau = to waste water

Differences:

perdre = to lose / to misplace / to waste time
- perdre ses clés = lose your keys
- perdre du temps = waste time
dépenser = to spend (money, energy)
- dépenser de l’argent = spend money (not automatically “waste”)

Here we want the idea of wasting food, so gaspiller is the natural verb.

Why is alors used here, and could we use donc instead?

Alors in this sentence means “so / therefore”, expressing a consequence:

Nous ne voulons pas gaspiller de nourriture, alors nous gardons les restes…
→ We don’t want to waste food, so we keep the leftovers…

You could also say:

…, donc nous gardons les restes…

Differences:

alors is very common in spoken French and can sound a bit more conversational.
donc is also common; it can feel slightly more neutral or formal in writing.

Both work here and keep the same basic meaning.

Why is it les restes in the plural, and what does it mean exactly?

Les restes literally means “the remains / the leftovers” and is almost always used in the plural when talking about leftover food.

les restes = the leftovers (of a meal)
You can specify: les restes du dîner = the dinner leftovers

It’s plural because it refers to various remaining bits of food, not one single item. French simply uses the plural form by default for “leftovers.”

Why do we say le lendemain instead of demain?

Demain means tomorrow (from now), relative to the moment of speaking.

Le lendemain means “the next day” relative to some other reference point in time (often a past or narrative context).

In your sentence, le lendemain suggests:

Talking about a general habit or telling a story: we keep the leftovers for the next day (after that meal).
If you were just speaking about tomorrow from now, you’d say demain:
- Nous gardons les restes pour demain. = We’re keeping the leftovers for tomorrow (from now).

Both can be correct but le lendemain is more “story-like” or habitual, relative to when the meal happens.

What is the role of pour in pour le lendemain? Is it like “for” in English?

Yes, pour here corresponds to “for” expressing intended time or use:

pour le lendemain = for the next day
pour demain = for tomorrow

Other similar uses:

C’est pour ce soir. = It’s for tonight.
Je le garde pour toi. = I’m keeping it for you.

So pour introduces the purpose or target time of keeping the leftovers.

Why is there an article in les restes and le lendemain, but not in de nourriture?

Different rules are at work:

After a negation, partitive articles du / de la / des usually become just de:
- Affirmative: gaspiller de la nourriture
- Negative: ne pas gaspiller de nourriture → That’s why there’s no article word between de and nourriture here.
Les restes and le lendemain are not in a negative structure, so they take normal definite articles:
- les restes = the leftovers
- le lendemain = the next day

So:

The lack of article in de nourriture is due to the negation rule.
Les / le are just regular definite articles.

Could we replace nous with on in this sentence? Would it sound more natural?

Yes, in everyday spoken French you would very often hear on instead of nous:

On ne veut pas gaspiller de nourriture, alors on garde les restes pour le lendemain.

Differences:

nous = “we”, more formal or neutral, often used in writing and careful speech.
on (informal subject pronoun) commonly means “we” in conversation.

Grammar note: with on, the verb is conjugated like 3rd person singular:

on veut, on garde, not ~~on voulons~~ or ~~on gardons~~.

Is de in de nourriture the same as “of” in English?

Not really. English “of” corresponds to de in many contexts, but here de is part of the partitive structure (especially after negation):

ne pas gaspiller de nourriture = not to waste (any) food

It doesn’t mean “of food” as in “a plate of food”:

une assiette de nourriture = a plate of food

In your sentence, de essentially expresses “some / any (indefinite quantity)”, not a simple “of.”

How would you literally break down the sentence structure in English?

Word by word / chunk by chunk:

Nous = we
ne … pas = do not (negation)
voulons = want
gaspiller = to waste
de nourriture = (any) food
alors = so / therefore
nous gardons = we keep
les restes = the leftovers
pour le lendemain = for the next day

Putting it together literally:

We do not want to waste any food, so we keep the leftovers for the next day.