When the two sentences are combined using the pattern "as...as":
He runs fast. I run fast.
--->He runs as fast as I run fast.
--->He runs as fast as I do.
--->He runs as fast as I.
Is the procedure correct?
Does the first "as" function like "so" and the second like "like"?
Thanks for explaining this to me!!
Olympic Gold, Silver and Bronze medalists in a 400m race all run fast.
Gold medal winner runs fast.
Silver medal winner runs fast.
Gold medal winner runs as fast as Silver medal winner. (?) That would be a tie, and both would be awarded a gold medal.
My focus is on syntax, not on semantics. Thanks.
(1) He runs as fast as I run fast..
(2) He runs as fast as I do..
(3) He runs as fast as I..
The underlined expressions are called comparative clauses. The crucial property of comparative clauses is that they are structurally 'reduced' in some way, usually obligatorily.
The second "as" is a preposition which is in construction with the first "as" (called the 'governor') which is an adverb.
In (1), there is no reduction and consequently the sentence is unacceptable. In (2) the comparative clause has been reduced to just "I do", where "do" is a pro-form meaning "run fast", so it now becomes acceptable.
In (3) the comparative clause has been reduced still further to just the subject of the clause, a pronoun. But "I" is very formal and best replaced by "me":
(4) He runs as fast as me".
Here, "me" is not a reduced clause, but a pronoun functioning as object of the preposition "as".
Does that answer your question?
Wow!!Thank you so much~~Paul!!
But, in some grammar books, the second "as" is thought to be a conjunction. Is it? Thanks!
Thank you, Paul!
Then, in this case, "You look much more beautiful than my sister (does)",
can "than" be viewed as a preposition in modern grammar? thanks!