Questions & Answers about Pulma ratkesi lopulta.
Because these are two different verbs:
- ratketa = to be solved, to come undone, to resolve itself
- ratkaista = to solve something
So:
- Pulma ratkesi lopulta. = the problem got solved / was solved in the end
- Joku ratkaisi pulman lopulta. = someone solved the problem in the end
This is a very common Finnish distinction: one verb is intransitive and describes something happening, while the other is transitive and takes an object.
Pulma is nominative singular.
In this sentence it is the subject of the verb:
- pulma = the problem / puzzle
- ratkesi = got solved
- lopulta = finally / in the end
So pulma is the thing that underwent the change.
Because ratketa is an intransitive verb here. It does not take an object in this meaning.
Compare:
Pulma ratkesi.
The problem got solved.
→ no objectHän ratkaisi pulman.
He/she solved the problem.
→ pulman is the object
That is why you see pulma in the nominative, not an object form.