I think (1) is OK but (2) is not acceptable.
(1) Do what you know is right.
(2) What do you know is right?
Do you agree?
Thank you in advance
Seiichi MYOGA
I’m assuming “know” in both cases mean “are sure.”
i think : what’s right do you know? 
Both are acceptable, but don’t carry the exact same meaning.
#1 is an imperative instructing you to do as you know is right (i.e. legally, morally, ethically, etc. correct).
.
#2 is a question asking you as to what you know to be right or correct? It’s asking for information about what the correct or right answer, solution, resolution, duty, obligation, etc. actually is.
Hello Seiichi Myoga,
Both of your sentences are fine in my book too. A context in which you could use (2) might be something like the following.
Further examples of the same sort of pattern:
- What do you think is true?
- How much would you say is enough?
- Which one do you think will win?
[color=darkblue]_________________________
[size=84]“If you don’t know where you are going, any road will get you there.” ~ Lewis Carroll[/size]
I appreciate both of you, Skrej and Esl_Expert, for your help and comments.
My thanks also go to Tedshi for taking interest in my post.
Both are acceptable, but don’t carry the exact same meaning.
As Tedshi might have suggested, I should have added something to ensure that “know” means “are sure”
(1’) Do what you know is right [color=red]for your future.
Now (1’) should work, don’t you think? (If it does work, I’d appreciate it if you could let us know.)
…do as you know is right (i.e. legally, morally, ethically, etc. correct).
I know that “know” means three things when it has a clause as its object: “RECOGNIZE,” “BE SURE,” and “HAVE INFORMATION.” Here you’re required to exercise the power to judge whether or not something belongs to a category such as like ethics. So “know” will be used as “RECOGNIZE.” Right?
#2 is a question asking you as to what you [color=red]know to be right or correct?
LDCE4 gives us the pattern “know somebody/something to be something” under the subcategory of “BE SURE.” So “know” must mean “are sure.”
I know that in my reading experience, we can extract something out of the embedded sentence that works as a complement of the verb “know (=recognize)” when the smaller clause is a relative clause.
And what I wanted to know was if it is also possible to use “know” as a bridge verb when it means “be sure.” But it would help non-native speakers of English a lot more when the contrast is stark, so I tried (in vain after all) to devise a minimal pair of wh-movements (one for a wh-question and another for a relative clause construction).
A context in which you could use (2) might be something like the following. …
Thank you for this. We’re so accustomed to what is called “context-free” grammar, but actually “know” requires more context than comprises a single sentence.
Further examples of the same sort of pattern: …
I know verbs can divided broadly into two types: factives or non-factives.
For non-factives like “say,” “think,” or “believe,” I think learners will have no or little difficulty understanding. As far as “know” is concerned, learners learn something like this:
(i) a. Do you know who married John?
b. *Who do you know married John?
As a result, it is getting still more difficult to understand why something like (2) is possible.
Seiichi MYOGA
Yes the first one is more acceptable than the second one. The second one makes no sense