Learn Hardcore French: L’ampoule du couloir est cassée; j’appuie sur l’interrupteur, mais rien ne s’allume. - The hallway bulb is broken; I press the switch, but nothing turns on.

Because of elision. The definite articles le and la become l’ before a vowel sound or a mute h to make pronunciation smoother. Since ampoule starts with a vowel, you say l’ampoule. The same rule explains l’interrupteur (from le interrupteur).

Why does cassée have an extra -e?

Cassée is an adjective (a past participle used adjectivally) and must agree with the noun it describes. Ampoule is feminine singular, so cassé becomes cassée. If it were plural: cassées (feminine plural) or cassés (masculine plural).

For a dead light bulb, should I say cassée or grillée?

Cassée means the bulb is physically broken (e.g., the glass is shattered).
Grillée is the usual word for a bulb that’s burned out. You’ll also hear colloquial options like HS (hors service), foutue, or claquée.

What does du couloir mean, and why not de le couloir?

Du is the mandatory contraction of de + le. So l’ampoule du couloir means “the hallway’s light bulb” or “the bulb for the hallway.”
Nuance: du couloir indicates association/possession (“the hallway bulb”), whereas dans le couloir indicates location (“the bulb in the hallway”).

Why is it j’appuie sur l’interrupteur and not j’appuie l’interrupteur?

With the meaning “to press a button/switch,” French uses appuyer sur + noun. So: j’appuie sur l’interrupteur, appuyer sur un bouton, appuyer sur la touche Entrée.
Bare appuyer without sur means “to support/lean” (e.g., appuyer une échelle contre le mur).

Is interrupteur the right word for a wall switch?

Yes. Un interrupteur is a wall light switch. Un bouton is a (push) button. You might also encounter commutateur (technical), disjoncteur (circuit breaker), and prise (socket/outlet).

Why is there a semicolon here, and how is it spaced in French?

The semicolon links two closely related clauses: the bulb is broken; I press the switch. In French typography, a (thin, non‑breaking) space is traditionally placed before ; (e.g., cassée ; j’appuie). In everyday digital writing many people omit it, but adding the thin space is the typographic norm.

Why is it rien ne s’allume rather than rien s’allume or rien n’allume?

Negative subject words like rien (“nothing”) pair with ne before the verb: rien ne + verb. So: rien ne s’allume is the standard form.
Rien n’allume would mean “nothing turns [something] on,” which uses transitive allumer and would need a direct object. That’s not the intended meaning.
Rien s’allume (without ne) sounds ungrammatical in standard French.

Why s’allume and not just allume?

Allumer is transitive: “to turn on [something].”
S’allumer is intransitive/pronominal: “to light up, to come on (by itself).”

J’allume la lumière. (I turn on the light.)
La lumière s’allume. (The light comes on.) Hence: rien ne s’allume (“nothing comes on”).

Can I drop ne in speech here?

In casual speech, people often drop ne, but with rien as subject they usually rephrase:

Standard: Rien ne s’allume.
Colloquial: Y a rien qui s’allume. or Ça s’allume pas. Plain Rien s’allume is not idiomatic.

Why not use ne … pas instead of ne … rien?

Ne … pas negates a verb in general (“not”). Ne … rien means “nothing.”

Ça ne s’allume pas. = It doesn’t turn on.
Rien ne s’allume. = Nothing turns on/comes on.
You choose based on what you want to negate.

What tense is used here, and how would I say it in the past?

It’s in the present: est, j’appuie, ne s’allume. To recount a completed past event, use the passé composé:

L’ampoule du couloir était cassée; j’ai appuyé sur l’interrupteur, mais rien ne s’est allumé.

How do I pronounce the tricky words?

l’ampoule: [lɑ̃pul] — “lahn-POOL”
couloir: [kulwaʁ] — “koo-LWAR”
j’appuie: [ʒapɥi] — “zhah-PWEE”
l’interrupteur: [l‿ɛ̃tɛʁyptœʁ] — “lan-teh-reup-TEUR”
rien: [ʁjɛ̃] — “ryeh(n)”
s’allume: [salym] — “sa-LOOM”

Why is it j’appuie with -uie? What’s the conjugation pattern?

Appuyer is an -yer verb with a spelling change: the stem y becomes i before a silent ending.

Present: j’appuie, tu appuies, il/elle appuie, nous appuyons, vous appuyez, ils/elles appuient.
That’s why you see -uie in the singular and -yons/-yez for nous/vous.

Could I say La lampe du couloir instead of L’ampoule du couloir?

Yes, but it’s a different thing. Ampoule is the bulb itself. Lampe is a lamp/fixture (a table lamp, floor lamp, or sometimes the whole light fitting). If you mean the light bulb specifically, ampoule is the precise word.

Does ampoule mean anything else?

Yes. Ampoule also means “blister” (e.g., une ampoule au pied = a blister on the foot). Context disambiguates; with du couloir, it clearly means a light bulb.