Amendment v. then describe three present-day situations where this law might give a citizen important protections from a potentially abusive government

One situation would be the double-jeopardy. It is a situation when the country wants to put you on trial multiple times. According to the fifth amendment, a federal court can't put you on trial multiple times for the same offense. This is done to prevent having the federal court put you on trial until the jury decides that you're guilty. If a case is acquitted then there can be no retrial.

Another situation is self-incrimination. If you know what you've done or haven't done and you don't want to talk about it then you don't have to talk about it. The amendment protects you from having to divulge information that might incriminate you even further. It is your right to remain silent.

Another situation is having a grand jury. Only a grand jury may indict a person. In a real life situation, a court might decide to decide that you're guilty and punish you without a jury in case you were a political opponent or something similar. This is unconstitutional and illegal and the fifth amendment protects you from it.