Lähden kotiin vasta sitten, kun kokous päättyy.

I will leave for home only when the meeting ends.

Breakdown of Lähden kotiin vasta sitten, kun kokous päättyy.

• minä: I
• koti: the home
• -iin: to
• lähteä: to leave
• kokous: the meeting
• päättyä: to end
• vasta sitten kun: only when

Questions & Answers about Lähden kotiin vasta sitten, kun kokous päättyy.

Why are the verbs in the present tense (lähden, päättyy) even though this sounds like a future situation?

Finnish commonly uses the present tense for future meaning when the time is clear from context (here, the when-clause). So Lähden can mean I leave / I’m leaving / I will leave, depending on context. If you want extra clarity, you can add a time word (e.g. huomenna) or use other structures, but the present is the normal choice.

What does vasta add here?

Vasta signals “not until / only (at that point)”. It sets a limit: leaving happens only after the condition is met. In practice, vasta often corresponds to English not until.

Why does it say vasta sitten, kun ...? Why both sitten and kun?

This is a common paired structure: vasta sitten, kun ... = “only then, when ...”.

• kun introduces the time clause (when the meeting ends)
• sitten reinforces the “then”-idea and links nicely with vasta for emphasis.
  You can often drop sitten without changing the basic meaning (see below), but keeping it can sound more explicit/rounded.

Can I say Lähden kotiin vasta kun kokous päättyy without sitten?

Yes. Lähden kotiin vasta kun kokous päättyy. is very natural and means the same thing.
Including sitten adds a bit of emphasis like “only then”, but it’s not required.

Why is there a comma before kun?

Because kun kokous päättyy is a subordinate clause. In Finnish, subordinate clauses are normally separated with a comma from the main clause:
Lähden kotiin, kun kokous päättyy.
With vasta sitten, kun..., the comma is especially expected.

Why is it kotiin and not koti or kotona?

Because kotiin is the illative case meaning “(to) home”—movement toward home.

• kotiin = to home (direction)
• kotona = at home (location)
• kotoa = from home (source)

What are the dictionary forms of the verbs, and how do these forms work?

• lähden comes from lähteä = to leave / to go (away)
  
  • lähden = “I leave / I’m leaving” (1st person singular)
• päättyy comes from päättyä = to end
  
  • päättyy = “it ends” (3rd person singular)

Why is kokous in the basic form and not in a case like kokouksen?

Here kokous is simply the subject of päättyy: “the meeting ends.” Subjects are typically in the nominative (basic form).
You might see kokouksen päätyttyä in a different structure (see another question), where kokouksen would be genitive.

Could the word order be different in the kun-clause?

Yes, Finnish word order is flexible. The neutral order is subject + verb: kun kokous päättyy.
But kun päättyy kokous is also possible, often for stylistic reasons or emphasis. In everyday neutral speech/writing, kun kokous päättyy is the most straightforward.

Is there an alternative way to express this idea without vasta?

A very common alternative is a negative + ennen kuin (“before” → “until” in English):

• En lähde kotiin ennen kuin kokous päättyy. = I won’t go home until the meeting ends.
  This is extremely natural and often the closest structural match to English not until.

Can the kun-clause be replaced with a non-finite/participle structure?

Yes. A common more “compressed” option is:

• Lähden kotiin vasta kokouksen päätyttyä.
  Literally: “I leave home only after the meeting having-ended” → only after the meeting ends.
  This is a bit more formal/compact than the kun-clause.

How should I pronounce tricky parts like Lähden, kotiin, päättyy?

Key points:

• Finnish stress is usually on the first syllable: LÄH-den, KO-tiin, PÄÄ-ttyy.
• Vowel length matters: kotiin has a long ii sound at the end (-iin), and päättyy starts with long ää.
• Double consonants are longer: päättyy has tt, which should be held longer than a single t.