I have a question too. Is it always incorrect to say, "I knew he has a brother"?
********** NOT a teacher **********
Hello, birdeen's call.
(1) Is it "always incorrect" to say
I knew (that) he has a brother?
(2) I most respectfully suggest that the answer is: NO.
(3) Of course, learners should follow "the rule." Therefore:
I knew that he had a brother.
(4) I know, however, that you are an advanced learner and that you
want to know
why.
(5) I think that I have found a wonderful answer in a book by the
famous grammarian Otto Jespersen.
(6) If I understand him correctly, he says that native speakers use the
past tense in the second part (
had) because of "mental inertia" (that is
-- in my words, not the professor's --
mental laziness). He explains that
we start with a past
(knew), and "mental inertia" prevents us from
realizing that we are now moving to the present. Here is his great
example:
You are here!!! I didn't know!!!
Logically the sentence should be:
I didn't know that you
are here!
The professor says that when we start with
didn't know, our mind is
moving so fast that we just continue speaking in the past (
were here).
(7) Logicially, then, your sentence "should" be:
I knew that he
has a brother (if his brother is still living). But
"the rule" tells us that the sentence is "bad" English.
(8) By the way, this whole subject comes under the heading of
sequence of tenses. When you have time, please google
that term. You will probably find some great results.
THANK YOU for your question. I learned a lot.