grammar - Wh question structure

What you look like.
What do you look like?

When forming the wh question, do I need to use a verb or auxiliary verb in between wh and subject?

What · he said · turned out to be true?
What · did he say · turned out to be true?

What · you opened it · with?
What · did you open it · with?

What do the above sentences mean?

Answer

All full questions* require a finite auxiliary verb^† (that is, an auxiliary verb tensed for either past or present) before the subject. When the verb in the sentence is a construction with an auxiliary, this is accomplished by switching the subject and the auxiliary. When the verb is a lexical verb with no auxiliary, it is accomplished with DO-support: the tense is removed from the verb and put on a form of DO before the subject:

He is John Smith. → Is he John Smith?
He is [who]. → Who is he?

He has gone to town. → Has he gone to town?

He has gone [where]. → Where has he gone?

You look like an executive. → Do you look like an executive?
You look like [what]. → What do you look like?

Your second sentence, however, confuses two different constructions. There What is not an interrogative, a question word, but a relative pronoun heading a clause which acts as a noun phrase. The statement form would be:

[_Subject What you said] [_Verb turned out] [_Complement to be true].

Consequently, the question form would be:

Did what you said turn out to be true?

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* As Peter Flom points out, questions may be truncated very substantially in discourse context.
^† BE is always considered an auxiliary, even when it is the only verb.