assistant TO vs. assistant OF What's correct: Asisstant to adviser or Assistant of adviser?

What does ‘The Present Continuous + always’ emphasize? I’ve known that the Present Continuous with always is used to express annoyance or irritation. But recently I’ve read that the present continuous with always can also describe something which happens frequently: My girlfriend is always cooking me special meals! I wonder if there’s any difference in meaning if I would use present simple instead of the present continuous in this case. My girlfriend always cooks me special meals.

Past Continuous vs. Past Perfect Continuous Which of these tenses I should use in this sentence? Last time we spoke I mentioned that book I was reading. Last time we spoke I mentioned that book I’d been reading. I want to say that at the time I spoke to that person I was in the middle of reading - start reading before that point and finished some time after. Thanks!