Zatvori vrata, molim te, jer je sada hladno.

Yes. Zatvori is the imperative form, meaning close!

In this sentence, it is the 2nd person singular imperative, so it is used when speaking to one person informally.

It comes from the verb zatvoriti (to close, perfective).

So:

• zatvoriti = to close
• zatvori! = close!

Because the sentence is giving an instruction/request, Serbian uses the imperative here, just as English does.

Yes, zatvori is for one person informally.

If you are speaking:

• to one person formally, or
• to more than one person

you would usually say:

• Zatvorite vrata, molim vas, jer je sada hladno.

So the forms are:

• zatvori = close! (singular informal)
• zatvorite = close! (plural or formal singular)

This is very similar to the ti / vi distinction in Serbian.

Great question. Vrata is one of those Serbian nouns that is grammatically plural even when it refers to one door.

This type of noun is called pluralia tantum — a noun that normally exists only in the plural form.

So:

• vrata = door / doors, depending on context

In the sentence Zatvori vrata, it means Close the door.

Even though English uses singular door, Serbian uses the plural-form noun vrata.

Here, vrata is in the accusative case, because it is the direct object of zatvori.

You are closing what?
→ vrata

For this noun, the accusative form is the same as the nominative form:

• vrata = nominative
• vrata = accusative

So even though the case is accusative, the form does not change.

Yes, in this sentence molim te means please.

Literally, molim comes from moliti (to ask, beg, request), so word-for-word it is something like I ask you. But in normal speech, molim te is a very common and natural way to say please to one person informally.

• molim te = please (to one person, informal)
• molim vas = please (formal or plural)

So:

• Zatvori vrata, molim te = Please close the door

Yes. Serbian word order is fairly flexible, and molim te can appear in different places.

For example, all of these are natural:

• Zatvori vrata, molim te, jer je sada hladno.
• Molim te, zatvori vrata, jer je sada hladno.
• Zatvori, molim te, vrata, jer je sada hladno. (possible, though a bit less neutral in everyday speech)

The version in your sentence is very natural and common.

Because Serbian often does not use a dummy subject like English it.

English says:

• It is cold

But Serbian simply says:

• Hladno je

Literally, that is more like:

• Cold is

The word je is the 3rd person singular present of biti (to be).

So:

• hladno je = it is cold / it’s cold

Serbian does not need a separate word corresponding to English it in this kind of weather or general-condition expression.

In this sentence, hladno is being used in an impersonal predicate expression, meaning cold in a general environmental sense.

So:

• hladno je = it is cold

This is different from describing a noun directly:

• hladna soba = a cold room
• hladna voda = cold water

Here, hladno does not agree with a noun. It describes the general situation or atmosphere.

English speakers often want to look for a hidden subject, but in Serbian this kind of expression works without one.

Jer means because.

So:

• jer je sada hladno = because it is cold now

It is a very common conjunction for giving a reason.

You may also hear:

• zato što = because

For example:

• Zatvori vrata, molim te, jer je sada hladno.
• Zatvori vrata, molim te, zato što je sada hladno.

Both are correct. Jer is short and very common in everyday speech.

Both mean now.

• sada = now
• sad = now

Sad is simply a shorter, very common form in everyday speech.

So these both sound natural:

• jer je sada hladno
• jer je sad hladno

The version with sada may sound a little more complete or slightly more careful, while sad is extremely common in conversation.

The commas help separate parts of the sentence clearly.

In:

• Zatvori vrata, molim te, jer je sada hladno.

the commas do two things:

1. They set off molim te, which works like an inserted polite expression.
2. They separate the main request from the clause introduced by jer (because).

So the structure is:

• main command: Zatvori vrata
• polite insertion: molim te
• reason clause: jer je sada hladno

In writing, this punctuation is normal and helpful.

Yes, to some extent. Serbian word order is more flexible than English word order, although some versions sound more natural than others.

For example:

• Molim te, zatvori vrata, jer je sada hladno.
• Jer je sada hladno, zatvori vrata, molim te. (possible, but more marked/emphatic)

The original version is very natural because it gives:

1. the request first,
2. then the polite softener,
3. then the reason.

That is a very common pattern in Serbian.

Because Serbian often uses the perfective imperative when asking someone to do a single complete action.

Here, the speaker wants one completed result:

• the door should end up closed

So zatvori is the natural choice.

If you used an imperfective form, it would usually sound different in meaning or style, often focusing more on process, repetition, or a different nuance.

For a simple everyday request like Close the door, the perfective imperative zatvori is exactly what you would expect.

A few common ways:

1. Use vi instead of ti:

   • Zatvorite vrata, molim vas, jer je sada hladno.

2. Use a softer phrasing:

   • Molim vas, zatvorite vrata, jer je sada hladno.

3. Use a question-like polite request:

   • Možete li da zatvorite vrata? Sada je hladno.
   • Možete li zatvoriti vrata? Sada je hladno.

So the original sentence is polite enough in an informal context, but if you are speaking to a stranger, an older person, or a group, zatvorite and molim vas are better choices.