As an adjective:
* "Please keep the separate piles of laundry."
* "The twins have separate bedrooms."
* "She has a separate bank account for her business."
As a verb:
* "We need to separate the good apples from the bad ones."
* "The students separated into groups for the project."
* "The government is trying to separate families at the border."
As an adverb:
* "The two groups marched separately to the rally."
* "The children were told to play separately."
* "I would like to address each point separately."
As a noun:
* "There is a separate entrance for employees."
* "The contract has a separate clause about liability."
You can also use "separate" in a phrase:
* "Separate and distinct"
* "Separate and apart"
* "Keep them separate"
The way you use "separate" will depend on the specific meaning you want to convey.