* Simple past tense: The accident occurred at the intersection of Main Street and Elm Street.
* Present perfect tense: The changes have occurred gradually over the past few years.
* Future tense: The eclipse will occur next week.
* Formal writing: The conference occurred in London last month.
* Informal writing: A problem occurred with the internet connection.
Here are some more examples:
* "The meeting will occur at 10:00 AM."
* "The earthquake occurred suddenly and without warning."
* "An unexpected event occurred that delayed our travel plans."
* "We can't be sure when the next solar flare will occur."
* "The error seems to occur only when the program is running in debug mode."
Remember that "occur" generally refers to events or happenings. It's not usually used to describe actions taken by people.