Vart ska du lägga din ryggsäck när du kommer hem?

In standard Swedish, vart is used for direction (to where?), while var is used for location (where?).

Here, the sentence asks where you are going to put the backpack, so the idea is movement toward a place. That is why vart fits well.

• Vart ska du lägga den? = Where are you going to put it?
• Var är ryggsäcken? = Where is the backpack?

In everyday speech, some speakers use var in places where standard grammar would prefer vart, but vart is the safest choice here.

Ska is the present tense of skola, and here it helps express a future action, often with the sense of are going to or will.

So:

• ska lägga = are going to put / will put

In this sentence, it is not mainly about obligation. It sounds more like asking about someone’s intended future action.

Because it comes after ska.

In Swedish, after a modal-like verb such as ska, kan, vill, måste, the next verb is usually in the infinitive.

So:

• ska lägga = are going to put
• kan lägga = can put
• vill lägga = want to put

The finite verb in the sentence is ska, not lägga.

In Swedish wh-questions, the normal order is:

question word + finite verb + subject + rest

So here:

• Vart = question word
• ska = finite verb
• du = subject

That gives:

Vart ska du lägga din ryggsäck...?

This is similar to English inversion in questions, but Swedish follows its own verb-second pattern very consistently.

Lägga usually means lay or put down, often with the idea that something ends up lying somewhere.

A backpack is something you often place on the floor, on a chair, on a bed, etc., so lägga sounds natural.

Some related verbs are:

• lägga = lay/put something down
• ställa = stand/set something upright
• sätta = set/place, often for smaller things or in certain expressions
• placera = place/position, more formal or neutral

So lägga din ryggsäck is a very normal choice.

In Swedish, when you use a possessive like min, din, hans, hennes, vår, etc., you normally use the noun in its indefinite form.

So:

• din ryggsäck = your backpack
• not din ryggsäcken

This is different from English, where the noun form does not visibly change.

Compare:

• en ryggsäck = a backpack
• ryggsäcken = the backpack
• din ryggsäck = your backpack

Ryggsäck means backpack.

It is a common noun, and its forms are:

• en ryggsäck = a backpack
• ryggsäcken = the backpack
• ryggsäckar = backpacks
• ryggsäckarna = the backpacks

The word is made up historically from rygg (back) + säck (sack/bag).

Because när du kommer hem is a subordinate clause, not a main question.

After a subordinating word like när (when), Swedish normally uses subject + verb order:

• när du kommer hem = when you get home

If it were an independent question, then you would say:

• När kommer du hem? = When are you coming home?

So the difference is:

• subordinate clause: när du kommer hem
• main question: när kommer du hem?

Because hem often already carries the idea of movement to home/homeward.

So Swedish commonly says:

• komma hem = come/get home
• gå hem = go home
• åka hem = go home/travel home

But when talking about being at home, Swedish uses hemma:

• vara hemma = be at home

So:

• komma hem = movement
• vara hemma = location

This is completely normal in Swedish.

In time clauses introduced by words like när (when), Swedish often uses the present tense even when the meaning is future.

So:

• när du kommer hem literally looks like when you come home
• but in natural English it is when you get home

English does something similar:

• We say when you get home, not usually when you will get home

So this part is actually quite close between the two languages.

In modern Swedish, du is the normal singular word for you, and it is used in most situations, even many polite or formal ones.

So in a sentence like this, du is exactly what you would expect.

Swedish does not work like languages that regularly switch between informal and formal second-person pronouns. For most everyday purposes, du is standard.

Then the main clause would still follow Swedish verb-second word order.

You could say:

När du kommer hem, vart ska du lägga din ryggsäck?

Notice that the finite verb ska comes before the subject du in the main clause.

So:

• Vart ska du lägga din ryggsäck när du kommer hem?
• När du kommer hem, vart ska du lägga din ryggsäck?

Both are correct. The difference is mostly about emphasis and sentence flow.