I was thinking about ways to make elven magic unique and decided they should use familiars. As I described them a long time ago, a familiar works basically like a replacement for a spellbook: a beginning elf PC would pick an animal of 1 HD or less, probably a dog, cat, or raven. By communing with their familiar, elven spell-casters can restore their spells. They can also see through their familiar's eyes, but they won't often put the familiar at risk, since if they lose their familiar, they have to get a replacement before they can prepare spells again.
But you know that communicating with a familiar is going to raise questions about what the familiar understands. My concept is: familiars are ordinary animals except for the parts mentioned above. They can understand their master's intent, but only simple verbs like "run" or "scratch" or "eat", and concrete nouns like "man", "woman", or "tree". They don't understand abstract concepts, like "baron", although an M-U can commune with their familiar to send an image of a particular baron, then command "find and follow". They can convey basic emotion to their masters, so they can warn of immediate danger.
Optionally, the familiar's ability to communicate gets better as the magic-user's level increases. Double the M-U's level to get the equivalent intelligence. At Level 2 (Int 4,) the familiar can remember short sequences of commands. At Level 5, the familiar can understand Common completely, the way any Int 10 NPC would be able to. At Level 6, the familiar can learn to speak one or two languages, plus two more languages for each level beyond that.