[wrholt]

Hi, Chris,

Rusty's links are a good place to start. One critical item is that in the middle of a word the spellings "r" and "rr" have different pronunciations.

Your observation that "r" (single letter) sounds a lot like the single-flapped "d" as in the American pronunciation of "butter", "ladder" and "latter" is correct. You might notice that this flap sound in English occurs only when the first syllable is stressed and the second syllable is unstressed. This may account for why you have trouble pronouncing "queréis", because the location of the stressed and unstressed syllables feels backward.