El vs de ?
I thought i was ok with 'needing the majority of something' being the ' plimulton de... ' But the previous question the answer was la plimulto el... So what is the difference and the defining characteristics for using el instead of de / da.
My handle on the grammer seems to be getting worse ( Woe is me)
In that sentence, both should be accepted, so I'm guessing there was something else wrong with your sentence. If I knew the exact sentence, I could look it up to verify it.
If you know a slavic language it has distinct similar prepositions probably. In Czech the preposition "z" or "ze" is the Esperanto "el" while there's lots of ways to say the equivalent of "de" including no preposition at all. In a context where "el" and "de" get confused, the Czech equivalent of "de" could be perhaps "od". So my current strategy for figuring out which it is, is to think of what I'd use in Czech, rather than English. Probably many other languages also have this distinction even though English does not. So if you know a language that does distinguish between the two prepositions, try thinking in that.
In fact, this is something that I've realized for a number of grammar rules. Certain concepts are closer to Czech than English (and vice-versa of course) and they then make more sense to me. It's usually things where English is vague or imprecise and you can think of a language which is not imprecise in that concept.