My Russian tutor is always telling me to only really pronounce the one stressed syllable in every word, and to sort of “swallow” all the other vowels. (So, an “o” sounds like a beautifully sonorous “oh” when it’s stressed and more like a timid little “uh” when unstressed. Speaking Russian with a good accent involves a ton of vowel reduction. It sometimes totally changes the meaning of words, so you can’t really get away with skipping it, either.)
English vowels tend to be “swallowed” the same way, but of course native speakers rarely give it any thought. When you’re reading unfamiliar words in an unfamiliar language, though, it’s really hard not to sound out every syllable very clearly, one-by-one. My tutor insists I sound “so foreign and Ukrainian” when I speak like that, which obviously as a Muscovite she can’t allow.
Now, my Spanish tutor’s reminding us that it’s important to make every vowel very clear. (Spanish is, I think, supposed to have no vowel reduction whatsoever? At least when you’re an English girl trying to learn it?) It should be so much easier than “swallowing” the unstressed ones… if I hadn’t spent all those years working hard to reduce all my unstressed vowels for Russian.