Put something down e.g. The exam is over. Please put your pens down.
Take something down e.g. The police took the offensive posters down.
Turn something down e.g. We’re trying to sleep. Turn the volume down.
Write something down e.g. I wrote his number down and I’ll call him later.
Knock down a building/person by a car etc e.g. She was knocked down by a bus.
Calm down e.g. You’ll pass the exam. Calm down.
Slow down e.g. What happened? You’re speaking too fast. Slow down.
Break down (stop working) e.g. Our car broke down on the highway yesterday.
Cut down on (reduce) e.g. I have to cut down on junk food. I’m always eating it.
Turn someone/something down (refuse) e.g. They offered me the position but I turned it down.
Shut /close down (stop doing business) e.g. The mall shut down as it wasn’t making any profit.
Let someone down (disappoint) e.g. He was expecting me to do well but I let him down.