alive & by the turn of

Q
1.The building collapsed and many people were buried alive.
[Why do we use an adjective"alive" after "were buried"? I thought it should be an adverb....]

2.By the turn of the 20th century, the bodybuilding craze started to pick up steam.
[What does it mean "by the turn of ~"? How can I explain it?]

Thank you very much.

A
1. This is an obscure point of grammar that is
difficult to explain. There might be several ways
to try to explain this. First, there is no adverb version of
the adjective "alive." For example, the adj. "smooth"
has an adverb version "smoothly," and the adj. "weak"
has an adv. version "weakly," but many adjectives do
not have this type of adv. version. One of these is
the adj. "alive": there is no adv. "alively."

However, even if there were such an adv. as "alively,"
in sentences with the structure: Subject--intransitive
verb or transitive verb in passive voice---_______,
such as this one, if the "_____" is an adj., it modifies
the subject, and if the "_____" is an adv., it modifies
the verb. For example, the adj. "rich" has an adv.
version "richly." In the sentence "They were buried
rich.", "rich" modifies "They," that is, they were rich
people who were buried. In the sentence "They
were buried richly.", "richly" modifies the verb: they
are buried in an expensive funeral.

In the sentence "They were buried alive.", "alive" modifies
"They": the people were alive when they were buried.
We're not talking here about them being buried in a
lively manner: even if there were such an adv.
as "alively," it could not be used here.

Still another way of explaining this is that the phrase
"buried alive" is a standard expression that is used
all the time. There are no other words that can be
used as substitutes in this phrase.

Yet another way of explaining it is that this sentence
is elliptical. Over hundreds of years it has been shortened
from the longer, "The building collapsed and many
people where buried while they were still alive.",
for the sake of brevity.

2. The phrase "the turn of the ____ century" means the
beginning of the ___ century. So "the turn of the 20th
century" means the start of the 20th cent., that is,
the year 1900. This phrase is probably metaphorical,
having its origin in the turning of a page in a book.
When you turn the page of a book, the "old" page that
you just read disappears and a new page appears.
Similarly, at the "turn" of the century, the previous
century disappears, so to speak, and the new century
appears.

轉貼自
http://mb.sparknotes.com/mb.epl?b=2437&m=1311145&f=1&t=369919#1311145