Breakdown of Apud la fenestro staras vazo kun verda planto, kiun mia amikino aĉetis hodiaŭ.
Questions & Answers about Apud la fenestro staras vazo kun verda planto, kiun mia amikino aĉetis hodiaŭ.
Esperanto word order is fairly flexible. Putting Apud la fenestro first gives the location first, and then staras vazo introduces what is there. It is a very common descriptive pattern, especially in scene-setting.
So vazo is still the subject, even though it comes after the verb. Vazo staras apud la fenestro is also correct, but the original sounds a bit more natural for introducing the scene.
In Esperanto, the subject does not have to come before the verb. The main clue is the ending: vazo has no -n, so it is not a direct object.
Also, the verb staras is intransitive here, so it does not take a direct object anyway. The sentence is saying that a vase is standing there, not that someone is standing a vase.
After a preposition like apud, Esperanto normally uses the basic noun form, not the accusative -n. So apud la fenestro means beside the window or by the window.
You only get -n after a preposition in special cases, usually when you want to show movement toward something. Here there is no movement; it is just location.