Learn Hardcore French: On met les assiettes dans le lave-vaisselle après le dîner. - We put the plates in the dishwasher after dinner.

On is grammatically third person singular (like il/elle), but in conversation it usually means “we”.
Nous is perfectly correct but sounds more formal or written, or it may be used for emphasis.

So:

On met les assiettes… ≈ “We put the plates…” (neutral, very common)
Nous mettons les assiettes… = also “We put the plates…”, but sounds more formal or emphatic in speech.

Both are correct; this sentence just uses the natural, everyday on.

Why is the verb met and not mets or mettons?

The verb is mettre (“to put, to place”). It’s irregular in the present tense:

je mets
tu mets
il / elle / on met
nous mettons
vous mettez
ils / elles mettent

Because the subject here is on, you must use the third person singular form: met.

So:

On met les assiettes… ✅
Nous mettons les assiettes… ✅
On mettons les assiettes… ❌

What exactly does mettre mean in this sentence?

Mettre is a very flexible verb. Its core meaning is “to put / to place”.

Here, On met les assiettes dans le lave-vaisselle means “We put the plates into the dishwasher.” It’s about moving the plates and placing them inside.

Other common meanings of mettre (not in this sentence, but useful):

mettre un manteau = to put on a coat
mettre la table = to set the table
mettre de l’argent de côté = to put money aside

The basic idea is always “to put / to place” something somewhere or into some state.

Why do we say les assiettes and not just assiettes without an article?

In French, you almost always need a determiner (article, possessive, etc.) in front of a noun, even in the plural.

English can say:

“We put plates in the dishwasher.” (no “the”)

French normally cannot drop the article like that. So you say:

On met les assiettes… = literally “We put the plates…”

Here les assiettes refers to “the plates” that were just used at this specific dinner. The definite article les is natural because the context is clear: it’s those plates.

What’s the difference between les assiettes and la vaisselle? Could we say On met la vaisselle dans le lave-vaisselle?

une assiette / des assiettes = a plate / plates specifically
la vaisselle = the dishes in general (all the items to wash: plates, glasses, cutlery, bowls, etc.)

So:

On met les assiettes dans le lave-vaisselle.
→ We (only) put the plates in the dishwasher.
On met la vaisselle dans le lave-vaisselle.
→ We put all the dishes in the dishwasher.

Both sentences are correct; they just focus on different things.

Why is it dans le lave-vaisselle and not au lave-vaisselle or en lave-vaisselle?

Dans usually means “in / inside” a place or container. Here the idea is literally putting the plates inside the dishwasher:

dans le lave-vaisselle = in the dishwasher, inside it

Alternatives:

au lave-vaisselle would sound wrong here; it could suggest “to the dishwasher” or “at the dishwasher”, not inside it.
en lave-vaisselle doesn’t work at all in this sense.

So dans le lave-vaisselle is the natural preposition to express putting objects inside the machine.

Why do we say le lave-vaisselle? What gender is it, and what does the hyphen mean?

Lave-vaisselle is masculine, so it takes le:

le lave-vaisselle = the dishwasher
un lave-vaisselle = a dishwasher

About the hyphen:

It’s a compound noun:
- laver = to wash
- la vaisselle = the dishes
  → literally “dish-washer”

French often uses hyphens in such compounds, especially with verbs + nouns:

un porte-monnaie (wallet; literally “carry-money”)
un tire-bouchon (corkscrew; literally “pull-cork”)

Plural: usually les lave-vaisselle (the noun “lave-vaisselle” often stays the same in plural in modern usage), though you may also see lave-vaisselles.

Why is it après le dîner instead of just après dîner? Are both correct?

Both can exist, but they’re not used in exactly the same way.

après le dîner = after the dinner / after dinner (the meal)
- Feels a bit more concrete and specific: after that meal you just had.
- Very standard and clear.
après dîner (without article) also exists; it often sounds a bit more literary or set-phrase-like and is less common in everyday speech in some regions.

In neutral standard usage, learners are safest with après le dîner.

Can après le dîner go at the beginning of the sentence?

Yes. French time expressions are flexible in position. You can say:

On met les assiettes dans le lave-vaisselle après le dîner.
Après le dîner, on met les assiettes dans le lave-vaisselle.

Both are correct. Putting après le dîner at the beginning just emphasizes the time a bit more.

Does the present tense On met… mean a general habit, or something happening right now?

In French, the present tense can express:

A general habit / routine
- On met les assiettes dans le lave-vaisselle après le dîner.
  → We (always / usually) put the plates in the dishwasher after dinner.
Something happening now (depending on context)
- (Someone’s explaining what they’re doing at that moment.)
- But in that case French doesn’t need an equivalent of English “are putting”; the simple present works.

So this sentence most naturally sounds like a habit or rule of the household, but context could make it about the present moment.

Is there a liaison between les and assiettes in pronunciation?

Yes, there is a liaison:

les assiettes is pronounced roughly [lez asjɛt] → you hear a z sound linking the words.

Other pronunciation points in the sentence:

On = nasal vowel, like “ohn” in the back of the nose.
met = [mɛ] (like “meh”); the -t is silent.
dans = nasal vowel [dɑ̃]; you don’t pronounce the final -s.
lave-vaisselle = [lav vɛsɛl], both l sounds are pronounced.
après = [apʁɛ]; the final -s is not pronounced.
dîner = [dine]; nasal n is pronounced, final -r is silent.