Brödrosten är varm nu, så låt den stå kvar en stund.

Brödrosten is the definite form, meaning the toaster.

• en brödrost = a toaster
• brödrosten = the toaster

In Swedish, the definite article is usually attached to the end of the noun:

• en stol → stolen
• en bil → bilen
• en brödrost → brödrosten

So Brödrosten är varm nu means The toaster is warm now.

Because brödrost is an en-word in Swedish:

• en brödrost
• therefore: den

In Swedish, pronouns often match the grammatical gender of the noun:

• en words → den
• ett words → det

So:

• Brödrosten → den

Even though English uses it for things, Swedish still has to choose between den and det.

Literally, it means something like:

let it stand/remain

But in natural English here, it means:

leave it there for a while
or
let it stay there for a while

The verb låta often means let or allow, and here it is used in an imperative:

• låt = let / leave

So låt den stå kvar is a very natural Swedish way to tell someone not to move something.

Swedish often uses verbs like stå (stand), ligga (lie), and sitta (sit) for the position of objects.

So even though English might simply say leave it there, Swedish often says:

• stå = stand
• ligga = lie
• sitta = sit

A toaster is thought of as something that typically stands on a counter, so stå sounds natural.

In other words, Swedish is being a bit more physically specific than English here.

Kvar means remaining, left, or still there.

In this sentence, stå kvar means:

• remain standing there
• stay where it is
• be left in place

Examples:

• Stanna kvar! = Stay! / Remain here!
• Det finns lite kaffe kvar. = There is a little coffee left.

So låt den stå kvar means leave it where it is.

Because after låta in this kind of structure, Swedish normally uses the bare infinitive.

Pattern:

• låta + object + infinitive

So:

• Låt den stå kvar
• literally: Let it remain

Not:

• låt den att stå kvar ❌

This is similar to English let someone do something, where we also do not say let someone to do something.

Because låt is an imperative form — a command.

In Swedish, as in English, commands usually do not need an expressed subject:

• Kom hit! = Come here!
• Vänta! = Wait!
• Låt den stå kvar! = Leave it there!

The subject is understood as you.

So the full sense is:

...so (you should) leave it there for a while.

Here så means so in the sense of therefore or for that reason.

• Brödrosten är varm nu, så ...
• The toaster is warm now, so ...

This is a very common use of så as a conjunction linking cause and result.

It can also mean other things in other contexts, such as:

• så stor = so big
• så! = there! / like that!

But in this sentence, it clearly means so / therefore.

En stund means a while or a short time.

So:

• stå kvar en stund = stay there for a while
• vänta en stund = wait a moment / wait a while

It is a very common expression in Swedish.

Also note:

• stund is an en-word
• so it is en stund, not ett stund

Nu is an adverb meaning now, and Swedish often places time adverbs after the verb or after an adjective phrase in simple clauses.

So:

• Brödrosten är varm nu

is a natural word order meaning:

• The toaster is warm now

You could think of the structure as:

• subject: Brödrosten
• verb: är
• complement: varm
• adverb: nu

This is completely normal Swedish word order.

It can mean either, depending on context.

In this sentence, varm probably means something closer to:

• warm
• or even hot if the toaster has just been used

Swedish varm covers a range that overlaps with both English warm and hot, so the exact translation depends on the situation.

Because the sentence warns you to leave the toaster alone, English might naturally translate it as:

• The toaster is hot now, so leave it there for a while.

even though the Swedish word is still varm.

Yes, it is perfectly natural.

It sounds like something someone might say in everyday life, especially in a kitchen or after using the toaster.

A native speaker might also say similar things like:

• Brödrosten är varm, så låt den stå kvar lite.
• Den är varm nu, så flytta den inte än.
• Låt den svalna en stund.

But your sentence is idiomatic and clear.

Yes, that is possible, but there is a slight difference in feel.

• låt den stå kvar = leave it standing there / leave it where it is
• låt den vara kvar = let it remain / leave it there

Stå kvar is a little more concrete, because it refers to the toaster’s position as something standing on the counter.
Vara kvar is more general.

Both can work, but stå kvar feels especially natural for an object like a toaster.