[btilly]

That helps less than I'd like with the spoken language given that a trailing о or а are pronounced like а because it won't be stressed.

For non-Russian speakers, the two letters get the sound that you expect if stressed, and otherwise sound like а. This rule also applies to borrow words that were transliterated into Cyrillic. So the English computer becomes компью́тер, and the stress goes on ...пью́т... (the English ...put... bit of the word). As a result that first о became an а sound.

My wife's reassurances that Cyrillic is phonetic likewise didn't work out for me. You can't pronounce the written word correctly without knowing where the stress is. You can't write down the spoken word correctly without knowing which unstressed а sounds are written as о.

Of course this is far better than English spelling...

[hn_throwaway_99]

As a native English speaker who learned Russian years ago, the o/a thing never felt confusing to me, perhaps because it felt very similar to what English does. Syllables that aren't stressed tend to be pronounced faster with less of a hard sound, and that's just what the o -> a rule feels like to me.

I always felt like Russian was a pretty easy language to learn because it was so regular. Yes there are a lot of cases and declensions, but once you learn the rules, you can get like 95% of the way there, and then even the last 5% of exceptions are quite "regular exceptions", e.g. the "ogo" written -> "ova" pronounced rule.

[grishka]

That а/о thing is taught extensively in schools. There are formal rules for everything, but of course I don't remember any. What I do remember is these are called "безударные гласные" (unstressed vowels), and "проверочные слова" (test words?) are used to figure out whether it's о or а. The idea is iirc that you find a word with the same root in a different form where that syllable is stressed. Except sometimes there isn't one ¯\_(ツ)_/¯