Cu robinetul de închidere închis, debitul apei este mic.

This is a very common Romanian pattern: cu + noun + adjective/participle.

Here, cu robinetul de închidere închis means something like:

• with the shut-off valve closed
• when the shut-off valve is closed

So cu does not just mean a physical with here. It introduces a circumstance or condition.

A very literal breakdown is:

• cu = with
• robinetul de închidere = the shut-off valve
• închis = closed

So the whole opening phrase sets the condition under which the statement is true.

They come from the same verb family, but they are different parts of speech.

• a închide = to close
• închidere = closing / closure / shut-off (a noun)
• închis = closed (an adjective or past participle)

In this sentence:

• robinetul de închidere = shut-off valve
  Here închidere is a noun used after de, like valve for closing / shut-off valve.

• robinetul ... închis = the valve ... closed
  Here închis describes the valve’s state.

So Romanian uses both forms because they do two different jobs.

Robinetul means the valve / the tap, with the definite article attached to the end of the noun.

Romanian often puts the definite article at the end of the noun instead of using a separate word like the.

So:

• robinet = a valve / a tap
• robinetul = the valve / the tap

In technical or explanatory sentences like this, Romanian often prefers the definite form when referring to a specific component in a general statement.

Robinet de închidere is a technical expression meaning a valve whose function is to shut off flow.

Depending on context, it can be translated as:

• shut-off valve
• stop valve
• sometimes shut-off tap

The structure is:

• robinet = valve / tap
• de închidere = for closing / for shut-off

So de here links the noun to its function.

Because Romanian uses the genitive to mean the flow of the water.

• debitul = the flow / the rate of flow
• apei = of the water

So:

• apa = the water
• apei = of the water

This is a normal Romanian pattern:

• presiunea apei = the pressure of the water
• temperatura apei = the temperature of the water
• debitul apei = the flow of the water

In natural English, we often shorten this to water flow, but Romanian commonly uses the of the water structure.

Because apei is the genitive-dative singular form of apă.

The base noun is:

• apă = water

But after another noun, to show possession or relation, Romanian changes it:

• debitul apei = the water’s flow / the flow of the water

This change is very common with feminine nouns.

So the learner should notice that Romanian often marks of the ... not with a separate word, but by changing the noun form.

Because mic agrees with debitul, not with apa.

The subject of the main clause is:

• debitul apei = the water flow

The head noun here is debitul, which is masculine singular.

So the adjective must also be masculine singular:

• debitul ... este mic = the flow is small/low

If the noun were feminine singular, you would use mică instead.

Yes. Romanian often uses mic in contexts where English prefers low.

So:

• debitul este mic = the flow is low / small

In technical language, you may also see more specialized wording, but mic is perfectly normal and understandable.

So don’t translate too mechanically. Romanian mic can correspond to English small, low, or sometimes little, depending on context.

In this sentence, este is the normal and correct form.

• debitul apei este mic = the water flow is low

Romanian usually keeps the verb a fi (to be) in this kind of present-tense statement.

So unlike some languages that often omit is, Romanian normally says este here.

In casual speech, people may sometimes reduce or soften things in conversation, but in standard written Romanian, este belongs in the sentence.

Yes, but the given order is very natural, especially in technical explanation.

Current order:

• Cu robinetul de închidere închis, debitul apei este mic.

This puts the condition first, then the result.

You could also say something like:

• Debitul apei este mic cu robinetul de închidere închis.

But that is usually less elegant and less natural in formal explanatory style.

Romanian often places the condition first when explaining how something works.

Here it functions adjectivally: it describes the state of robinetul.

So in:

• cu robinetul ... închis

închis means closed and agrees with robinetul.

It comes historically from the past participle of a închide, but in sentences like this it behaves much like an adjective.

You can think of it as:

• robinetul este închis = the valve is closed
• cu robinetul închis = with the valve closed

No. In this sentence, cu does not suggest physical accompaniment in the English sense of together with.

Instead, it introduces a condition or state:

• with the valve closed
• when the valve is closed

This is an important usage of cu in Romanian. It can describe the circumstances in which something happens, not just possession or accompaniment.

So the phrase is about the valve’s state, not about a person with a valve.

That depends on context.

The word robinet can mean:

• tap
• faucet
• valve

In a technical sentence with de închidere, valve or shut-off valve is usually the best translation.

In household contexts, robinet often means tap or faucet.

So the surrounding context determines the most natural English word.