|break down||fail to function|
|have a physical or mental collapse|
|break in||interrupt a discussion|
|soften with use (shoes)|
|break off||discontinue (therapy, relationship)|
|break out||escape from prison, begin suddenly|
|break up||end a relationship|
I use the phrase "break down" to describe an action of explaining something step by step or in a very detail way, for example, "Yesterday, I broke down the solution of a problem to my friends."
There is one more phrase "break into", I sometimes use it to describe the action that a person does to get into a system (usually software) without authorize, for example, some hackers are trying to break into our system.
Please let me know, what you think about these usages.