(A) To stop or fail usually in a complete and sudden way (inseparable)
1. Negotiations have broken down.
2. The government’s argument broke down completely when new evidence came to light.
3. Their marriage had broken down and there was nothing we could do about it.
(B) To be overwhelmed by strong emotions (inseparable)
1. My mother is very emotional. I don’t want her to break down and weep if she hears the news.
2. My father left mom as he breaks down in anguish.
3. She broke down and started to cry.
(C) To stop working properly (inseparable)
1. Our car broke down on the highway.
2. This old motorcycle is constantly breaking down.
3. My car has broken down so I called my dad to pick me up.
(D) To remove a difficulty that prevents something from happening. (separable)
1. An unruly mob broke down police and stormed the courtroom.
2. His early experience enabled him to break down barriers between Scottish Catholics and Protestants.
3. The people could not enter the room because they could not break the gate down.