Use scene for a place where something happens or a part of a film or play, and seen for the past participle of see. Memory hook: seen is the word that follows have, has or had (I have seen it), while scene is something you can point to, like the scene of the crime.
The core difference
Scene is a noun for a place or episode; seen is a form of the verb see.
- scene — a place where something happens, a part of a film or play, or a public outburst: Reporters rushed to the scene of the fire.
- seen — past participle of see, used after have, has, had or be: Have you seen my keys?
- scene — also a group with a shared interest: She was deeply involved in the local music scene.
How to tell them apart
Scene is a noun and never a verb form. It can be a location (the scene of the accident), one section of a play or film (the final scene), a community (the music scene), or a fuss (He made a scene at the restaurant).
The mix-up usually happens in writing, because the two words sound alike. A quick test: put have or had in front of the word. I have seen it works, but I have scene it does not, because scene is a noun. If you could replace the word with place or episode, you want scene.