Sequence of tenses

Yoshi wrote:
I want to know if the following sentence is grammatical :"Did you know he is planning to go to China?"

I think 'is' should be 'was' because the main verb of the sentence is the past tense. Am I correct?

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Hi Yoshi,

The "sequence of tenses" never was a 'rule' of English.

Class time; be right back.

JTT: I'm back. As Jim mentioned in my absence, either would be okay. But what he didn't mention is that there are reasons we choose one or the other.

Yoshi, the first thing you're going to have to re-learn is that the old "rule" you were taught was wrong, wrong, wrong. There are many old prescriptive "rules" that were never an accurate reflection of the language. "Sequence of Tenses", [I think it's Jisei no icchi], was one of these errant "rules".

Reported speech goes far beyond the "He said that blah blah blah ..." Your example is also reported speech in a slightly different form.

"Did you know he is planning to go to China?" --->>> "I've heard that he's planning ..." OR "Somebody told me that he is planning to ..." .

Let's use an example sentence to help us along.

Imagine that this conversation took place between you, me and Satoko.

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JTT: It's class time. I'll be right back.

Satoko: What did JTT say, Yoshi?

Yoshi: He said that it was class time but that he would be right back.
==============

In your reply to Satoko, there are three verbs [that need concern us]; said, was, would.

Only one of these three verbs is a past tense and that verb is 'said'. The 'said' is the ONLY thing that had finished at the time of speaking.

At the time of speaking, "it IS class time." The use of 'was' only tells us that the speech is NOT a direct quote. It is merely a past tense FORM [notice, I said FORM] used to signal indirect speech.

The word 'would' is the historical past tense and in this case, as with other modal pairs, the historical past tense FORM is also used to signal indirect speech. It is NOT being used to discuss an actual finished event.

That's clear because at the time it was spoken, I hadn't come back, that is to say, it was a future, not yet happened event.