Generally you should be able to replace “i.e.” with “that is” and have your sentence make sense and follow grammar rules. Similarly you should be able to replace “e.g.” with “for example.”

It’s generally ok to write “namely” or “to wit” where you might write “that is [to say]” although “to wit” isn’t very common. For example:

> We use a primitive programming language, namely C++.

> We use a primitive programming language, that is to say C++.

> we mainly use a primitive programming language. C++, that is.

> we mainly use a primitive programming language, to wit C++

"i.e." abbreviates "id est", which transliterates from Latin to "that is"; "e.g.", "exempli gratia", "for (the sake of) example". Most other such abbreviations found in English originate and function similarly, such as "cf." ("conferatur", "compare"), "nb." ("nota bene", "note well"), "etc." ("et cetera", "and so on"), etc.

Most people don’t know enough Latin for such translations to help with writing sentences that conform to standard grammar.

True, but looking up abbreviations like these seems often to lead first to the Latin expansion, and figuring out what that means in English provides the necessary grammatical clue. Also, I'm enough of a linguistics nerd to like the way abbreviations like these work for their own sake, so I thought I'd share in case anyone else might be interested too.