Latin synonyms

Aren’t they a pest? For some can be used interchangeably but others can’t even though they may mean the same thing.

For example:
Pugna and proelium
They both can mean fight in the sense of war, i.e. battle. But only pugna means fight as in a fist fight.

Or forsitan and fortasse: they both mean perhaps but from what I understand forsitan is used with the subjunctive and fortasse with the indicative.

Let’s make this thread about synonyms. If you have a question about two words that are synonyms yet aren’t sure if they can be used interchangeably post them here and wait till a more experienced Latinist can answer your question. I’ll start.

In and contra, in the sense of against.

Can they be used interchangeably?

even though they may mean the same thing

Or not. That’s the richness of language and part of the value proposition in learning to read works in their original.

What methodology do you propose for comparing two words (in and contra in your example) that would be different from simply reading the respective articles in the Oxford Latin Dictionary?

Simply because some words may be translated by the same word in English in certain contexts does not mean that they mean the same thing.

Were you replying to my original post or to RandyGibbons? What you said pretty much defines the meaning of this thread but it doesn’t answer my question.