These other words cannot be used because they are simply not interchangeable in meaning, or require different conjugations of verbs as a result.
To remind someone is different than to announce to someone, because remind implies that it has already been said.
To hardly have started, it means you have indeed started. Nearly, means you haven't yet started.
Asking for directions is in the plural because to get to a place, generally requires a number of directions. It would be singular if it were as such: "Can I ask you what direction ___ is?"
You can use "capable", but you'd have to change the sentence.
"I was finally capable of getting back" - but this does not necessarily imply that you did in fact, get back. Thus the meaning is not the same.
To arrest someone and to charge someone - these are two different processes of law and are not interchangeable.