Hon vinkade från tåget, och jag viskade att vi skulle ses snart.

Both are in the past tense (the Swedish preterite).

• vinkade = waved
• viskade = whispered

A very common pattern in Swedish is that many verbs end in -ade in the past tense:

• vinka → vinkade
• viska → viskade

So the sentence is clearly describing something that happened in the past.

In Swedish, you normally need to state the subject explicitly, just as in English.

• Hon vinkade = She waved

Unlike in some languages, Swedish usually does not drop subject pronouns in ordinary sentences. So hon is necessary here.

Från tåget literally means from the train. In this sentence, it means she was waving while being on or at the train, with the action coming from that location.

A natural English translation is often:

• She waved from the train

This strongly suggests she was on the train, for example at a window or door, as it was leaving.

If you said på tåget, that would mean on the train, but it would describe location more directly rather than the source point of the waving.

Tåget is the definite form of tåg:

• ett tåg = a train
• tåget = the train

Swedish often uses the definite form when the thing is specific or already understood from the situation. Here, it is a particular train, not just any train.

Also note how Swedish usually puts definiteness at the end of the noun:

• tåg
  • -et → tåget

Here att means that.

• jag viskade att vi skulle ses snart
• I whispered that we would see each other soon

It introduces a subordinate clause, just like English that.

In English, that is sometimes optional:

• I whispered (that) we would meet soon

In Swedish, att is very commonly kept in this kind of sentence.

Yes, skulle often means would, but it has a few related uses.

Here it is best understood as a kind of future seen from the past:

• vi skulle ses snart = we would meet soon / we were going to see each other soon

Because the main verb is already in the past (viskade), Swedish often uses skulle to express something that was future at that past moment.

So the timeline is:

• first: I whispered
• after that: we were going to meet soon

This is one of the most important things in the sentence.

Ses comes from se (to see), but here it has a special meaning: see each other / meet.

• vi ska se = we will see
• vi ska ses = we will see each other / meet

So:

• vi skulle ses snart = we would meet soon

This -s form can function like a passive or reciprocal form, and with ses it is very commonly used in the sense of meeting each other.

Literally, the form may look a bit like that, but in normal Swedish this expression is usually understood as:

• we would meet soon
• we would see each other soon

It is a standard idiomatic way to talk about people meeting.

So while the grammar behind -s forms can be complex, the practical meaning here is simply meet / see each other.

Yes, definitely.

• vi skulle ses snart
• vi skulle träffas snart

Both can mean we would meet soon.

There can be a slight nuance:

• ses = see each other, meet
• träffas = meet, get together

In many contexts they are very close in meaning. Ses often feels very natural when talking about seeing someone again.

Swedish adverb placement is flexible, but this word order is very natural.

• vi skulle ses snart = we would meet soon

Here snart comes at the end, where time expressions often go. That is a very common placement.

You could sometimes move adverbs around for emphasis, but this version is straightforward and idiomatic.

Yes. The sentence follows normal Swedish main-clause word order.

Main clause 1:

• Hon vinkade från tåget

Main clause 2:

• och jag viskade att vi skulle ses snart

Swedish main clauses usually follow verb-second (V2) word order, meaning the finite verb comes early in the clause. Here that pattern is perfectly normal:

• Hon
  • vinkade
• jag
  • viskade

Inside the subordinate clause after att, the order is also normal:

• att vi skulle ses snart

Not always. In Swedish, a comma before och is often optional when joining two main clauses.

So both of these can be acceptable:

• Hon vinkade från tåget och jag viskade att vi skulle ses snart.
• Hon vinkade från tåget, och jag viskade att vi skulle ses snart.

The comma can make the sentence feel a little clearer or more literary, especially when the clauses are fairly long. But it is usually not strictly necessary.

Not necessarily.

Here hon vinkade från tåget simply says that she waved. It does not say who she waved to.

If you want to say who the waving was directed at, Swedish often uses åt:

• Hon vinkade åt mig = She waved at me

So in your sentence, the focus is on the action and where it happened, not on the person receiving the wave.

Yes, in this sentence snart matches English soon very well.

• vi skulle ses snart = we would meet soon

It means before long, in the near future, or after a short time. This is one of the most direct vocabulary matches in the sentence.