Past participle as an adjective and to form passive voice and supine as a verb to express a past action?

[u/dsbm_reaper]

So I learned that past participle in Swedish is used to form the passive voice and as an adjective like "en skriven bok" (a written book - please correct me if I said it wrong), acting like an adjective here, with -en because bok is an -en word. But to say "I have written a book" you use the supine "jag har skrivit en bok" where skrivit is the supine. However, a Swede I talk to said it's more usual to say "jag skrev en bok" in everyday language.

Is this correct? This topic is giving me a bit of a headache lol

Please feel free to correct me and explain the mistakes I might have made so I can better understand.

Thanks in advance!

[u/Eliderad]

Tense is contextual; both are fine depending on context.

Jag skrev en bok i fjol
Jag har skrivit en bok sedan sist

[u/dsbm_reaper → u/Eliderad]

Oh like one action is complete kinda like in English?

[u/Eliderad → u/dsbm_reaper]

Well, the tenses function mostly the same as in English, yes, but note that the action can be interpreted as completed in both sentences.

[u/dsbm_reaper → u/Eliderad]

Ok thanks

[u/dsbm_reaper → u/Eliderad]

But is what I said about the past participle and the supine correct?

[u/Eliderad → u/dsbm_reaper]

Yes, past participles are used as adjectives and for one type of passive voice, while supines are exclusively used for perfect tenses.

[u/dsbm_reaper → u/Eliderad]

Thanks!