Early Modern Italian (?) in relation to Latin (reading)

I hope this is not too off-topic for this section of the forum.

I introduced myself a couple years ago and got apparently solid advice on returning to Latin and getting started with Greek – advice that I admit I have done little with. Excuses, excuses.

I am here to ask if anyone knows of resources that would be helpful for reading what I guess is Early Modern Italian - Leonardo, to be specific. I don’t know whether the same kinds of resources exist or are useful in the same way as for classical languages – this is why I’m asking.

I have a smattering of old Latin and some modern Romance. My strongest suit is modern Slavic. I have a dilletante’s knowledge of Old English. Does anyone know of a grammar or grammar / reader that could be useful for this? I will be grateful for any notions. Thank you.

If by Leonardo you mean Da Vinci, it would be silly to suggest anything other than “Learn Italian”. Of course it has changed in some respect, but Italian has had from quite early on a solid tendency to favour writing in Tuscan, which morphed into Modern Standard Italian. Leonardo writes solid Italian which no modern educated Italian would fail to understand, the few slips that you will nevertheless find being an inevitable but small price to pay for the shortcut. Besides there are no manuals of “Early Modern Italian” for people who know no Italian. You’ll get an overview of the problem if you google “questione della lingua”.

A few years back there was a controversy about a translated Machiavelli’s The Prince — with Italians, rightly to my mind, complaining that treating Machiavelli as a form of Italian so early it justified translation was a dumbing down. But that’s Machiavelli, with an obvious latinate syntax (he will write, for instance, “timeva che non venisse” echoing Latin’s “timebat ne veniret”, instead of the usual romance “timeva che venisse”). Leonardo famously had no Latin (!), very unusual for a Renaissance man, so you don’t even have that sort of problem.