Aujourd'hui, le lave‑vaisselle est en panne.

The comma separates the time expression Aujourd'hui (“today”) from the rest of the sentence.

• It’s common and stylistically natural in French when a time, place, or comment is put at the start:
  
  • Aujourd'hui, je suis fatigué.
  • En France, on parle français.
• The comma is optional here. You can also write:
  
  • Aujourd'hui le lave‑vaisselle est en panne.

Yes, Aujourd'hui is treated as a single word meaning “today.”

Historically it comes from several words:

• au (à + le) = “on the”
• jour = “day”
• d'hui (from Latin hodie) = “of today”

Over time this fused into aujourd'hui.
The apostrophe shows elision (d' + hui) but you never split it in modern French; you always write it as one word.

Rough guide using English-like sounds (not perfect):

• Aujourd'hui ≈ “oh-zhoor-DWEE”
  
  • au → “oh”
  • jour → “zhoor” (soft j like in “measure”)
  • liaison: jour_d'hui → you hear a d sound linking into “hui”
  • hui → like “wee” but starting with a slight “h” that is not really pronounced; it blends with the d.

Syllables: a‑jourd‑hui (2–3 depending how you count, but felt as one rhythm group).

Not usually.

• Aujourd'hui = “today” (all of this day, or “as of today”).
• Maintenant = “now” (this moment in time).

In your sentence:

• Aujourd'hui, le lave‑vaisselle est en panne.
  → It’s out of order today (maybe all day).

Maintenant, le lave‑vaisselle est en panne is possible but emphasizes “right now,” and in many contexts aujourd'hui sounds more natural.

In French every noun has a grammatical gender.

• lave‑vaisselle is masculine, so it takes le (singular masculine definite article).
• You say:
  
  • le lave‑vaisselle (the dishwasher)
  • un lave‑vaisselle (a dishwasher)
  • mon lave‑vaisselle (my dishwasher)

There is no rule from the form of the word that clearly tells you the gender; you just have to learn lave‑vaisselle = masculine.

Context decides which article sounds natural:

• Le lave‑vaisselle est en panne.
  → “The dishwasher is broken.”
  Assumes the one known in context (probably the one in this kitchen/house).
• Mon lave‑vaisselle est en panne.
  → Emphasizes it’s my dishwasher.
• Un lave‑vaisselle est en panne.
  → Sounds like “A dishwasher is broken” (one among several), which is unusual in a home context but possible in, say, a large restaurant or store.

In everyday conversation at home, le lave‑vaisselle is the most neutral and common.

Literally: “washes dishes” or “dish‑washer.”

• lave = “washes” (from laver, to wash)
• vaisselle = “dishes,” “crockery,” “tableware”

It’s a compound noun written with a hyphen: lave‑vaisselle.
Many modern compound nouns in French use a hyphen when two words act together as a single noun.

The noun itself does take a plural s:

• un lave‑vaisselle → des lave‑vaisselles

But note:

• In writing, only the last element takes the plural s (just like des porte‑monnaies, des gratte‑ciels).
• In speech, singular and plural sound the same; you only see the plural in writing and from the article (un / des, le / les).

No. That’s a different word.

• un lave‑vaisselle = a dishwasher (the machine)
• du liquide vaisselle or du liquide pour la vaisselle = washing‑up liquid, dish soap

So don’t use lave‑vaisselle for the detergent.

Literally: “to be in breakdown / in a state of breakdown.”

• être en panne = “to be broken / out of order / not working.”
• It’s a fixed expression used mainly for machines, devices, vehicles:
  
  • La voiture est en panne. = The car has broken down.
  • L’ascenseur est en panne. = The elevator is out of order.

They’re close, but with a nuance:

• est en panne
  
  • Suggests a real fault or breakdown.
  • Very standard and common for machines.
• ne marche pas / ne fonctionne pas
  
  • More general: “doesn’t work / isn’t working.”
  • Can be temporary, maybe user error, not necessarily a “breakdown.”

In many everyday situations you can use either:

• Le lave‑vaisselle est en panne.
• Le lave‑vaisselle ne marche pas.

Both will be understood.

Because être en panne is a set expression in French. You normally use:

• être en panne (to be broken)
• tomber en panne (to break down / to stop working)

Avoir une panne exists but is used differently, more like “to have a failure/breakdown,” and more often with abstract or figurative uses (or in very specific technical contexts). For everyday talk about machines:

• Use être en panne for the state.
• Use tomber en panne for the moment it breaks.

• être en panne = to be broken / out of order (state)
  
  • Le lave‑vaisselle est en panne.
• tomber en panne = to break down / to stop working (event, change)
  
  • Le lave‑vaisselle est tombé en panne hier. = It broke down yesterday.

So you’d usually describe what happened with tomber en panne, and the resulting situation with être en panne.

In normal, correct French you need the verb:

• Aujourd'hui, le lave‑vaisselle est en panne.

Leaving out est is not standard. You might see similar structures in headlines or very informal note‑taking, but in normal speech and writing, the copula être must be there.

Yes, that’s perfectly correct:

• Aujourd'hui, le lave‑vaisselle est en panne.
• Le lave‑vaisselle est en panne aujourd'hui.

Both are fine.
Putting aujourd'hui at the beginning often emphasizes the time a bit more; at the end it can sound slightly more neutral or like an afterthought.

The form en panne itself does not change; it’s en + noun (panne, feminine singular). Because panne is a noun after a preposition, it stays the same:

• Le lave‑vaisselle est en panne. (masculine singular)
• La voiture est en panne. (feminine singular)
• Les machines sont en panne. (plural)

Only the subject (article and noun) changes; en panne stays identical.