Hendes ankomst passer stadig med vores planer, hvis toget ikke bliver mere forsinket.

Because sin/sit/sine is a reflexive possessive, and it normally refers back to the subject of the clause.

In this sentence, the full subject is Hendes ankomst. The person who owns the arrival is she, but the grammatical subject is actually arrival, not she as a separate subject pronoun. So Danish uses hendes.

A useful comparison:

• Hun ændrede sine planer. = She changed her own plans.
• Hendes ankomst passer stadig... = Her arrival still fits...

So here, hendes is the correct non-reflexive possessive.

Ankomst means arrival. It is a noun related to the verb at ankomme = to arrive.

Danish often uses nouns in places where English also can use nouns:

• hendes ankomst = her arrival
• vores afrejse = our departure

So the sentence is talking about the event of her arriving, not the action in verb form.

At passe med means something like to fit with, to match, or to be compatible with.

So passer stadig med vores planer means that her arrival is still compatible with the plans.

Related expressions:

• passe med = fit/match
• passe til = suit/go with
• passe by itself can also mean look after in other contexts

Here, med is the natural preposition because the idea is matching with the plans.

Stadig means still.

In a normal Danish main clause, the finite verb usually comes early, and adverbs like stadig often come after it:

• Hendes ankomst passer stadig med vores planer.

That placement is very natural and neutral.

Compare the English idea:

• Her arrival still fits with our plans.

So stadig is simply the adverb still, placed in a standard Danish position after the finite verb passer.

Because hvis means if, and the sentence expresses a condition.

• hvis toget ikke bliver mere forsinket = if the train does not get any more delayed

Use hvis when something is conditional or uncertain.

By contrast, når means when, usually for something expected or assumed to happen:

• Når toget kommer, går vi. = When the train arrives, we leave.

So in your sentence, the idea is not when the train gets more delayed, but if it gets more delayed. That is why hvis is correct.

Because Danish subordinate clauses have different word order from main clauses.

In a main clause, the negation ikke usually comes after the finite verb:

• Toget bliver ikke mere forsinket.

But after a subordinating conjunction like hvis, ikke usually comes before the finite verb:

• hvis toget ikke bliver mere forsinket

So this is a very important pattern:

• main clause: subject + finite verb + ikke
• subordinate clause: conjunction + subject + ikke
  • finite verb

This is one of the most common word-order differences learners notice in Danish.

Here bliver means becomes/gets.

So bliver mere forsinket means gets more delayed or becomes more delayed.

This is not best understood as a passive meaning like is delayed. The sentence is about a change of state:

• it is already delayed
• the question is whether it will become even more delayed

So bliver here is functioning like gets/becomes.

Because forsinket is an adjective that naturally forms its comparative with mere rather than with an ending like -ere.

So:

• forsinket = delayed
• mere forsinket = more delayed
• mest forsinket = most delayed

This is very common with longer adjectives and with adjectives that look like past participles.

So Danish works much like English here:

• delayed → more delayed
• forsinket → mere forsinket

Because possessives in Danish usually replace the article, just as they do in English.

So:

• planerne = the plans
• vores planer = our plans

You do not normally say both together in a phrase like this.

That is why med vores planer is correct, not something like med de vores planer.

Sometimes stadig and endnu can both relate to the idea of still/yet, but they are not always interchangeable.

In this sentence, stadig is the most natural choice because it expresses continued validity:

• her arrival still fits with our plans

Endnu often leans more toward yet/still so far, depending on context.

So while learners may see overlap between the two words, stadig is the better and more idiomatic choice here.

It usually means our plans in the relevant situation, so it can be understood as specific from context even without anything extra.

Danish often leaves that kind of specificity to context, just as English does:

• our plans
• the plans we have made

So vores planer is perfectly natural here and does not need any extra wording unless you want to be more explicit.