1.The decade of the 1970's is sometimes called the Jazz Age.(Original sentence)
2.King James considered her a genius. (Original sentence)
3.Mrs Sanderson was elected President.(Original sentence)
All sentences seemed unatural to me because I haven't seen these sentence structures before.
I think sentence all three sentences need "as". Like this way in the sentences 1, 2, 3 "~called as~.","~her as a genius.", "~elected as~." to make sense. Am I understanding correctly? Or would you give me some explanations about these?
Here is how I see it:
1. "Mrs. Sanderson was elected president" is the passive of something like:
"The people elected Mrs. Sanderson president."
After verbs such as "elect" or "appoint," you may introduce the objective complement ("president") with the word
"as." Thus: The people elected Mrs. Sanderson as president." Passive: Mrs. Sanderson was elected as president (by the
2. For example: Everyone in the United States (and in the world) is waiting to see who will be elected (as) president in November.
(a) One expert, Mr. Walter Kay Smart in his English Review Grammar, says that some native speakers may prefer "as" if the complement ("president") is modified. Thus: Whom will the people elect as our president? / Who will be elected as our president (by the people)? ("president" is modified by "our.")
Let's look at your first two sentences.
"The decade of the 1970's is called the Jazz Age." The active is something like:
Writers call the 1970's the Jazz Age.
"King James considered her a genius." That is already the active. (The passive would be: She was considered a genius by King James)
Probably (repeat: probably) you cannot use "as" in those two sentences because the verbs "call" and "consider" do not allow "as."
But -- to show you how difficult English is -- Mr. Smart's book (if I understood him) says the following WOULD be OK:
King James regarded her as a genius. (Because you "regard someone as": "I considered him my friend" but "I regarded him as my friend.")
HAVE A NICE DAY!