Vi vandrade tillbaka till vandrarhemmet.

Both can translate as walked, but they are not always used the same way.

• gå / gick = the general verb to go / went or to walk / walked
• vandra / vandrade = to hike, to trek, or to walk for some distance

So Vi vandrade tillbaka till vandrarhemmet gives a sense of walking back on foot, possibly after an outing or over some distance.
If you said Vi gick tillbaka till vandrarhemmet, that would also be natural, but it sounds more neutral and less descriptive.

Tillbaka means back.

In this sentence, it shows that the movement is a return:

• Vi vandrade tillbaka ... = We walked back ...

It often works like English back in movement expressions:

• komma tillbaka = come back
• gå tillbaka = go back
• åka tillbaka = travel back

They do different jobs.

• tillbaka = back
• till = to, showing destination

So:

• tillbaka tells you the direction is a return
• till vandrarhemmet tells you where they returned to

Word-for-word, the sentence is roughly:

• Vi = we
• vandrade = walked/hiked
• tillbaka = back
• till vandrarhemmet = to the hostel

So the full sense is We walked back to the hostel.

Because Swedish often uses the definite form where English uses the.

• ett vandrarhem = a hostel
• vandrarhemmet = the hostel

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

• hem = home
• huset = the house
• vandrarhemmet = the hostel

So till vandrarhemmet means to the hostel.

It is made of:

• vandrarhem = hostel
• -et = the definite ending for many ett nouns

So:

• ett vandrarhem = a hostel
• vandrarhemmet = the hostel

Also, vandrarhem is itself a compound noun:

• vandra = wander / hike / walk
• hem = home

Historically, it is like walking-holiday home, but in normal usage it simply means hostel.

This is normal Swedish main-clause word order:

• Vi = subject
• vandrade = verb
• tillbaka till vandrarhemmet = adverbial/direction phrase

So the pattern is:

• Subject + verb + rest

This is very similar to English:

• We walked back to the hostel

Swedish is a V2 language, which means the finite verb usually comes in second position in main clauses. In this sentence, the subject comes first, so the verb comes right after it.

Yes. Vandrade is the past tense of vandra.

• infinitive: vandra = to hike / to walk
• present: vandrar = hike(s), am/is/are walking
• past: vandrade = walked / hiked
• supine: vandrat = walked / hiked (used with har)

Examples:

• Vi vandrar tillbaka. = We are walking / walk back.
• Vi vandrade tillbaka. = We walked back.
• Vi har vandrat tillbaka. = We have walked back.

This verb belongs to a very common weak-verb pattern where the past tense ends in -de.

Yes, absolutely.

Vandra can suggest:

• hiking
• trekking
• walking for some distance
• wandering on foot

So depending on context, natural translations could be:

• We walked back to the hostel.
• We hiked back to the hostel.
• We made our way back to the hostel on foot.

If the meaning has already been given to the learner as walked back, that is fine, but hiked back may sometimes be closer.

Usually it comes after the verb here:

• Vi vandrade tillbaka till vandrarhemmet.

That is the most natural placement.

You may sometimes see Swedish adverbs move around in other sentence types, especially when another element comes first:

• Till vandrarhemmet vandrade vi tillbaka.
  This is possible, but much less neutral and sounds more marked or literary.

For everyday Swedish, the original order is the one to learn first.

A rough English-friendly guide might be:

• Vi ≈ vee
• vandrade ≈ VAHN-dra-deh
• tillbaka ≈ til-BAH-ka
• till ≈ til
• vandrarhemmet ≈ VAHN-drar-hem-met

A few useful notes:

• Swedish a is usually broader than English a
• r is often clearly pronounced
• the stress is roughly on:
  • VANdrade
  • tillBAka
  • VANdrarhemmet

Exact pronunciation varies by dialect.

Usually, if they mean a youth hostel or hiking hostel, yes.

Vandrarhem is the normal Swedish word for that kind of accommodation.
It is not the same as:

• hotell = hotel

So:

• Vi gick tillbaka till hotellet = We went back to the hotel
• Vi vandrade tillbaka till vandrarhemmet = We walked back to the hostel

Yes, tillbaks exists as a variant of tillbaka, especially in speech and informal writing.

But:

• tillbaka is the standard written form
• tillbaks is more informal

So for learners, tillbaka is the safest form to use.

Because Swedish usually puts the definite article at the end of the noun instead of using a separate word like English the.

Compare:

• English: the hostel
• Swedish: vandrarhemmet

This is one of the most important structural differences between English and Swedish.

A few examples:

• en bil = a car
• bilen = the car
• ett hus = a house
• huset = the house
• ett vandrarhem = a hostel
• vandrarhemmet = the hostel