Hon stod vid grinden och vinkade, medan barnet ropade att hon inte fick glömma sin ryggsäck.

Stod is the past tense of stå = stand.

In Swedish, people often use posture verbs like stå (stand), sitta (sit), and ligga (lie) where English might simply use be.

So:

• Hon stod vid grinden = She was standing by the gate
• Hon var vid grinden would mean more simply She was at the gate, without emphasizing that she was standing

So stod gives a more visual, physical description.

Vid here means by, at, or next to.

So:

• vid grinden = by the gate

It suggests location near the gate, not necessarily on it or inside it.

Because grinden is the definite form: the gate.

• en grind = a gate
• grinden = the gate

Swedish usually adds the definite article as an ending:

• en bok → boken
• en grind → grinden

So vid grinden means by the gate, not just by a gate.

Medan means while.

It shows that two actions were happening at the same time:

• Hon stod vid grinden och vinkade, medan barnet ropade ...
• She stood by the gate and waved, while the child shouted ...

You could sometimes use när, but it would change the feel:

• medan emphasizes simultaneity
• när usually means when

So medan is the more natural choice here.

Here att introduces what the child shouted. It works like that in English.

• barnet ropade att ... = the child shouted that ...

This is indirect speech, not direct speech.

Compare:

• Barnet ropade: Du får inte glömma din ryggsäck!
  direct speech
• Barnet ropade att hon inte fick glömma sin ryggsäck.
  indirect speech

So att is there because the sentence reports the content of the shout.

Because this is a subordinate clause introduced by att.

In Swedish subordinate clauses, sentence adverbs like inte usually come before the finite verb.

So:

• main clause: Hon fick inte glömma sin ryggsäck.
• subordinate clause: ... att hon inte fick glömma sin ryggsäck.

This is a very important word-order pattern in Swedish.

A useful rule:

• main clause: verb before inte
• subordinate clause: inte before verb

Yes, fick is the past tense of få, and få can mean get, but it also often means may, be allowed to, or in negative sentences something like must not / shouldn’t.

Here:

• inte fick glömma literally looks like was not allowed to forget
• idiomatically it means mustn’t forget or shouldn’t forget

Compare:

• Du får inte glömma ryggsäcken. = Don’t forget the backpack.
• literally: You may not forget the backpack

So this is a very common Swedish way to express a warning or reminder.

Because sin is the reflexive possessive pronoun.

Swedish uses sin / sitt / sina when the possessor is the same as the subject of that clause.

Here, in the clause:

• att hon inte fick glömma sin ryggsäck

the subject is hon, so sin refers back to hon.

So sin ryggsäck means her own backpack.

If you used hennes ryggsäck, it would usually mean someone else’s backpack, not the subject’s own.

This is one of the biggest differences from English, because English uses her in both cases, but Swedish makes a distinction.

A natural direct-speech version would be:

• Barnet ropade: Du får inte glömma din ryggsäck!

Then in indirect speech it becomes:

• Barnet ropade att hon inte fick glömma sin ryggsäck.

Notice the changes:

• du → hon
• din → sin
• får → fick

That is why the reported version looks the way it does.

The main verbs are all in the past tense:

• stod = stood / was standing
• vinkade = waved / was waving
• ropade = shouted
• fick = was allowed to / mustn’t, in this context

This is normal in storytelling. The whole sentence is narrated from a past point of view.

Not always strictly necessary, but it is natural and helpful here.

Swedish comma use is often a bit more flexible than English comma use. A comma before a longer subordinate clause like this can make the sentence easier to read:

• Hon stod vid grinden och vinkade, medan barnet ropade ...

Many writers would keep the comma here for clarity and rhythm.