Lähtö on tunnin kuluttua, joten odotan vielä hetken.

Lähtö is a noun meaning departure (from the verb lähteä = to leave).
Lähtö on ... is a basic Finnish copula sentence: [noun] + on (is) + [time/place expression].
So it literally patterns like Departure is in an hour.

In time-measure expressions, Finnish commonly uses the genitive form (ending -n) for the amount:

• tunnin = of an hour / an hour’s (genitive of tunti)
  So tunnin kuluttua is the standard way to say in an hour (literally something like after an hour).

You’ll see the same pattern with other measures:

• päivän päästä = in a day
• kahden viikon kuluttua = in two weeks

Kuluttua is a postposition meaning after / from now by in these time expressions. Finnish often uses postpositions that come after their complement, unlike English prepositions.

Structure: [time in genitive] + kuluttua

• tunnin kuluttua = after an hour → in an hour
  It’s parallel in meaning to tunnin päästä (also very common).

Joten means so / therefore and it introduces a new clause. In Finnish, it’s normal to put a comma before clause-linking conjunctions like joten when they connect two full clauses:

• Lähtö on tunnin kuluttua, joten odotan vielä hetken.

Finnish usually doesn’t need subject pronouns because the verb ending shows the person.

• odotan = I wait / I’m waiting (1st person singular present)

You can say minä odotan, but it adds emphasis/contrast (like I as opposed to someone else).

Finnish present tense covers both depending on context.

• odotan can mean I wait (general/habitual) or I’m waiting (right now).
  Here, the context makes it clearly right now: you’re waiting because departure is later.

Vielä often means still / yet / a bit longer. Here it suggests continuing the waiting: I’ll wait a little longer.

Placement can shift emphasis slightly, but common options include:

• odotan vielä hetken (neutral/common)
• vielä odotan hetken (more emphasis on still)
• odotan hetken vielä (less common; can sound more afterthought-like)

Hetki = a moment.

• hetken is the accusative/genitive-looking total object form, used when the waiting time is seen as bounded/complete: wait for a moment (and then stop).
• hetkeä is the partitive and tends to sound more ongoing/indefinite: wait for a moment (for some time, not focusing on completion).

So odotan vielä hetken fits the idea: you’ll wait a short, specific extra amount of time.

Yes—these are very typical Finnish stem changes:

• tunti → tunnin: the stem shows nn in inflection (a common alternation)
• hetki → hetken: i often drops before certain endings (hetke- + n)
• lähteä → lähtö: the noun lähtö is derived from the verb and has a related but different stem

Recognizing these patterns helps a lot with reading and forming cases.

Yes. Finnish word order is flexible and often used for emphasis/topic:

• Lähtö on tunnin kuluttua. (neutral: talking about departure)
• Tunnin kuluttua on lähtö. (emphasizes the time: in an hour, it’s departure time)
• On tunnin kuluttua lähtö. (possible in some contexts, more marked)

The original is the most straightforward, neutral option.