Questions & Answers about Naš plan se često mijenja.
Se is a reflexive pronoun, but in sentences like this it mainly works as a marker that makes the verb intransitive.
- mijenjati = to change something (you need an object)
- Često mijenjamo plan. – We often change the plan.
- mijenjati se = to change, to be changing (no object; the subject changes itself / undergoes change)
- Naš plan se često mijenja. – Our plan often changes.
If you removed se and said Naš plan često mijenja, it would sound incomplete: Our plan often changes… (what?). You would expect an object after it. So se is necessary here to get the meaning changes (by itself / as something that undergoes change).