Hilfe, bitte bin mir nicht sicher, was ich falsch mache

Looks like typical crispy edges from low humidity or inconsistent watering (super common with bird of paradise). If the soil dries out completely between waterings, the tips brown first. I’d check that it’s getting bright light and water thoroughly when the top 2–3 inches are dry. You can trim the brown parts off they won’t turn green again.

Birds Of Paradise really aren’t meant to be grown indoors. I mean you obviously can… but they’re more trouble than their worth.

The tags saying “part shade” are with the intention of *landscaping*. Even in Florida we’ll plant them in full sun to get the best growth.

Just based off the dark green color I’m going to say low light is your issue. We’d be able to judge the extent of etiolation if you showed pictures of the whole plamt.

https://preview.redd.it/16wn29guxwjg1.jpeg?width=1080&format=pjpg&auto=webp&s=07ef74af5af872b50b9be1d0218df1659f46c71d

This is not an ideal place. Note the petiole length. Leaves should be “hugging” the central grow area and not be on long sticks.

As for watering; the entire genus comes from tropical South Africa. They *need* excellent drainage and moderate watering. They have extremely thick and fleshy roots & tolerate drought nicely. Their ideal soil mix is sandy / loamy; but 50% grit like perlite in pots is acceptable. When in doubt don’t water. Lots should dry out completely within a week