Laukku jäi pysäkille, joten menen takaisin hakemaan sen.

The bag was left at the stop, so I go back to pick it up.

Breakdown of Laukku jäi pysäkille, joten menen takaisin hakemaan sen.

• minä: I
• mennä: to go
• se: it
• joten: so
• -lle: to
• takaisin: back
• pysäkki: stop
• laukku: bag
• jäädä: to be left/stay
• hakea: to pick up

Questions & Answers about Laukku jäi pysäkille, joten menen takaisin hakemaan sen.

What does jäi mean here, and what is its base form?

Jäi is the past tense (imperfect) 3rd person singular of jäädä = to stay / remain / get left behind.
So Laukku jäi... literally means The bag stayed/remained..., and in natural English often corresponds to The bag got left (behind).

Why is it Laukku jäi and not something like Jätin laukun?

They focus on different things:

• Laukku jäi pysäkille (from jäädä, intransitive) = the bag ended up left behind / remained there (doesn’t explicitly say who caused it).
• Jätin laukun pysäkille (from jättää, transitive) = I left the bag at the stop (explicitly your action; object is laukun).

Why is pysäkille in the -lle form? Doesn’t -lle mean “to”?

Yes: pysäkille is the allative case (-lle) and often means to/onto. With jäädä, Finnish commonly uses -lle to mark the place where something remains after you leave or after movement is involved:

• jäädä asemalle / pysäkille = to be left behind at the station/stop (the “destination area” where it ended up)

You can also hear pysäkillä (adessive, “at the stop”) in some contexts, but pysäkille is very idiomatic with jäädä in this “left behind” sense.

What exactly is joten, and why is there a comma before it?

Joten means so / therefore and introduces a result. In Finnish it’s normal to put a comma before joten when it connects two clauses:

• Laukku jäi pysäkille, joten... = The bag was left at the stop, so...

Why is menen in the present tense if the first clause is past?

Finnish often uses the present tense to talk about an intended near-future action, similar to English I’m going back:

• Past situation: Laukku jäi... (it happened)
• Present/intention: menen takaisin... (what I’m going to do now)

You could also say menin if you mean you already went back.

What is takaisin grammatically, and where can it go in the sentence?

Takaisin is an adverb meaning back. It’s flexible in placement:

• menen takaisin hakemaan sen (very natural)
• menen hakemaan sen takaisin (can sound like “fetch it back” / return it)
• menen takaisin pysäkille hakemaan sen (more explicit: back to the stop)

Placement can slightly change what back attaches to (going back vs bringing back).

Why is it hakemaan and not hakea?

After many verbs of motion like mennä (to go), Finnish commonly uses the 3rd infinitive illative (-maan/-mään) to express purpose:

• mennä hakemaan = go (in order) to fetch

So hakemaan = to fetch as a purpose form, not the basic dictionary infinitive (hakea).

How do I break down the form hakemaan?

• Verb: hakea = to fetch / to get / to pick up
• 3rd infinitive: hakeminen (the “fetching” action as a noun-like form)
• Illative of that: hakemaan = “into fetching” → idiomatically to fetch (as a purpose)

So mennä hakemaan is literally something like “go into fetching,” but means “go to fetch.”

Why is the pronoun sen and not sitä?

This is about the Finnish object system:

• sen = total object (you mean fetching it as a complete, finished action: you’ll get the whole bag)
• sitä = partial object (often ongoing/incomplete, or “some of it”)

In menen takaisin hakemaan sen, the purpose implies a completed result (you intend to retrieve the bag), so sen is the natural choice.

What does sen refer to, and can it be omitted?

Sen means it and refers back to laukku (bag).
It can be omitted if context is very clear, but Finnish often keeps the pronoun for clarity:

• ...mene(n) takaisin hakemaan sen = go back to fetch it
  Without sen, it can sound slightly more abrupt or less specific, depending on context.