Both definite articles (before "turn" and before "millennium") are there because there it's understood that there is only one "turn of the millennium" -- at least in the most likely situation where the writer and the reader are living in and talking about the modern era. In other contexts, the indefinite article would be correct: - A turn of a millennium is typically a period of great social upheaval. (this is not 100% natural but grammatically correct) I haven't heard of this rule about using a definite article when the following noun is part of a phrase. There are many examples where it's not true: - A man of constant sorrow has seen trouble all his days.

"the" suggests something definite, "a" or "an" suggests multiple options. "The turn of the millennium" is correct. "a box of cereal" - there is more than one box of cereal. There is only one "turn of the millennium" (at least in a lifetime)

1. Grammatical rules do exsist. 2. They are very useful to language learners, especially with regard to those basic rules. Only with knowing these basic rules can we make sentences. 3. It seems impossible that grammarians find out every single grammatical rule of a language. 4. A lot of rules are very intricate so that it's almost impossible for a grammarian to completely explain even one grammatical rule. 5. It seems every grammatical rule has its exceptions. Therefore there are a lot of 'rules' that are not yet writtenin grammatical or usage books, so you'll find some phenomena that you cannot find a ready rule to explain; and it's not rare that come across some use cases that are against certain rules, or you'll find that some rules given by different writers (or even by the same one) conflict with each other. Every common language speaker has their complete complex grammar of their mother tongue: even they do not realize this at all. This kind of seemingly inborn special capacity for language is called 'language sense' or 'language sensibility'. In some sense, foreign language learning is acquiring this sensitivity, besides the vocabulary. ------------ On the 1st of January 2000, I opened my dream shop. I’d taken (1) an / - early retirement from my job at an insurance company, and (2) the / - turn of the millennium seemed (3) an / the ideal time to do it. (1) an : [[[ and I presume that it'd be 'I'd take' rather than 'I'd taken' in the original? ]]] but it's fine to say' John took early retirement last year'. (2) the (3) an: [[[ but I think 'the' is fine too, with no more context offered. It depends on wether there was only one or more possible 'ideal times' in the writer's mind]]].

Sasha...I feel like I am walking into a trap here...but I am going to say 'yes'...let's wait and see what other people say :-)

1 an 2 the 3 the потому что turn -- исчисляемое