"I have seated myself on the chair."
Translation:Ich habe mich auf den Stuhl gesetzt.
Really? Not even when the English sentence uses present perfect?
Although many teachers may tell you otherwise, preterite and present perfect are in fact not completely equivalent in German. The present perfect is neutral in terms of aspect (i.e. it doesn’t necessarily imply perfect aspect) but the preterite always implies non-perfect. Or in other words, you can always use present perfect instead of preterite, but there are situations where only present perfect is appropriate. Mostly when I’m focusing more on the result of the action than the action itself. For example, I would normally never say “Er starb” but only “Er ist gestorben” (unless maybe I’m telling a story and want to mentally transport the listener/reader to the very moment “he” dies).
To come back to the example sentence, the English implies that the result of “him” sitting down on the chair is somehow important to the present. I wouldn’t use preterite for that in German, no matter how formal I want to be.
Ahh so that's why they say Perfekt is used more often in conversation and Präteritum in stories. It makes sense now, with the distinction that the perfect aspect focuses more on the result of the action, while the non-perfect aspect focuses more on the process of the action itself (like when recounting a story). You raised a good example with "Er ist gestorben" and "Er starb". Thanks!
For translations out of the English simple past, generally both tenses in German will be accepted.
But for translations out of the English present perfect, generally only the German Perfekt is appropriate. If you can find a sentence where English present perfect accepts a translation in German simple past, please let me know as that exercise may have to be corrected.
See also the comment by AbunPang further up in response to Bekir978479.