sequence of tenses

[groopy7777]

I don’t see how to handle sequence of tenses.

He knows that the earth is round.
He knew that the earth is round.

I can understand the above two sentences. How about the following two sentences?

(a) I know he is fine.
(b) I knew that he is fine.

Generally speaking, I think that sentence (b) should be amended into “I knew that he was fine”, because tenses (knew and is) don’t match; however, If he is fine now, can I say “I knew that he is fine” to express that he is fine even now?

I want to know more about exceptional cases of sequence of tenses.

[riverkid]

Originally Posted by groopy7777

I don’t see how to handle sequence of tenses.

He knows that the earth is round.
He knew that the earth is round.

I can understand the above two sentences. How about the following two sentences?

(a) I know he is fine.
(b) I knew that he is fine.

Generally speaking, I think that sentence (b) should be amended into “I knew that he was fine”, because tenses (knew and is) don’t match; however, If he is fine now, can I say “I knew that he is fine” to express that he is fine even now?

I want to know more about exceptional cases of sequence of tenses.

First, Groopy, there is no "sequence of tenses". The change in tense is only a change in FORM and that change in form is only done to signal reported speech.

We know this is true because we can actually report the speech with a direct quotation. We choose according to what we want to say, not according to fictitious rules.