Example 1
Eliza ends every workout with forty-five minutes on the stationary bike.
The scenery may be awful, but a stationary bike is a great way to get fit in terrible weather. Stationary is the right word for the job in this sentence because it's describing a bike that's not going anywhere.
Example 2
Clint remained stationary until the spider scuttled out of the room.
Since Clint is paralyzed by fear, stationary is the correct word in this creepy-crawly sentence.
Example 3
Faith refuses to embrace email and still sends all of her correspondence on personalized stationery.
How quaint and time-consuming! In this sentence we're talking about Faith's fancy writing materials, so stationery is the way to go.