În bucătărie nu mai este nicio farfurie curată.

In this sentence, nu mai means no longer / not anymore / no more.

So nu mai este nicio farfurie curată literally means something like:

• there is no longer any clean plate
• more natural English: there are no clean plates left

A very useful pattern is:

• mai este = there is still / there is anymore
• nu mai este = there is no longer / there isn’t anymore

Examples:

• Mai este pâine. = There is still bread.
• Nu mai este pâine. = There is no more bread.

Romanian does not need a separate word like English there in existential sentences.

So instead of saying literally there is, Romanian often just uses este / sunt:

• Este o carte pe masă. = There is a book on the table.
• Sunt copii afară. = There are children outside.

In your sentence:

• În bucătărie nu mai este nicio farfurie curată.

Romanian simply uses este plus the noun phrase, where English would usually say there is/there are.

Because Romanian is built around nicio farfurie = not a single plate / no plate, which is grammatically singular.

So the structure is:

• nicio farfurie = singular feminine
• therefore este = singular verb

Literally, it is close to:

• There is not even one clean plate left in the kitchen.

Romanian can also express the idea with a plural noun:

• În bucătărie nu mai sunt farfurii curate.
  = There are no clean plates left in the kitchen.

Both are correct, but your sentence emphasizes not a single clean plate.

Nicio means no / not any with a feminine singular noun.

Here:

• farfurie = plate, feminine singular
• so you use nicio farfurie = no plate / not any plate

Compare:

• niciun băiat = no boy
• nicio fată = no girl
• niciun pahar = no glass
• nicio masă = no table

So nicio agrees with the gender of the noun it modifies.

In standard Romanian, nicio is written as one word when it functions as the negative determiner meaning no / not any.

So:

• nicio farfurie = no plate

It is different from nici o written as two words, which can mean something like not even one in a more literal or emphatic sense.

For most learners, the key rule is:

• use nicio = one word for no / not any before a feminine singular noun

În usually means in / inside.

So:

• în bucătărie = in the kitchen

For rooms and enclosed spaces, în is the normal preposition:

• în cameră = in the room
• în baie = in the bathroom
• în clasă = in the classroom

So În bucătărie is exactly what you would expect for in the kitchen.

After many prepositions, Romanian often uses the noun with the definite article included, but with some very common location expressions, the article may be omitted, especially in a general locative sense.

So both types exist in Romanian:

• în bucătărie = in the kitchen
• în bucătăria mea = in my kitchen
• în bucătăria restaurantului = in the restaurant’s kitchen

In your sentence, în bucătărie sounds natural and idiomatic as a general location: in the kitchen.

In Romanian, adjectives usually come after the noun.

So:

• farfurie curată = clean plate
• casă mare = big house
• copil bun = good child

That is the normal order. Romanian can sometimes place the adjective before the noun, but that is less neutral and can sound more expressive, literary, or emphatic.

So here farfurie curată is the standard order.

Because adjectives in Romanian must agree with the noun in gender and number.

Here:

• farfurie is feminine singular
• so the adjective must also be feminine singular
• therefore: curată

Compare:

• farfurie curată = clean plate
• farfurii curate = clean plates
• pahar curat = clean glass
• pahare curate = clean glasses

So curată matches farfurie.

Grammatically, the noun phrase nicio farfurie curată is the thing whose existence is being talked about, so yes, it functions like the subject of the existential statement.

But for an English speaker, it may help to think of the whole structure as an existential sentence:

• În bucătărie nu mai este nicio farfurie curată.
• literally: In the kitchen, there is no clean plate anymore.

Romanian often places the location first and the noun phrase after este, especially in these there is/there are-type sentences.

Yes. Romanian word order is fairly flexible.

For example:

• Nu mai este nicio farfurie curată în bucătărie.
• Nicio farfurie curată nu mai este în bucătărie.

These are possible, but your original sentence is very natural because it starts with the setting:

• În bucătărie = in the kitchen

That gives the sentence a smooth, normal flow: location first, then the statement.

Because nicio already acts as the determiner.

In English, compare:

• a plate
• the plate
• no plate

You do not say the no plate, because no already fills that determiner slot. The same idea applies in Romanian.

So:

• o farfurie = a plate
• farfuria = the plate
• nicio farfurie = no plate

Yes. In natural use, nu mai este nicio farfurie curată strongly implies there are no clean plates left.

Even though the grammar is singular (nicio farfurie), the meaning in context is often equivalent to English plural:

• There aren’t any clean plates left.

So learners should understand both levels:

• literal structure: not a single clean plate remains
• natural meaning: there are no clean plates left

Mai is a very common word with several meanings depending on context. In this sentence, with nu, it gives the meaning any longer / anymore.

Useful comparisons:

• Mai este apă. = There is still water.
• Nu mai este apă. = There is no more water.

So mai often adds the idea of still, and nu mai reverses it to no longer.

This is one of the most useful everyday Romanian patterns to learn.

A very natural plural version would be:

• În bucătărie nu mai sunt farfurii curate.

That means:

• There are no clean plates left in the kitchen.

Compare the two:

• nu mai este nicio farfurie curată = there is not a single clean plate left
• nu mai sunt farfurii curate = there are no clean plates left

The first is a bit more emphatic because it stresses not even one.