I have a question :
I was trying to think of possible sentences with "will" and "would" :
1) is this a correct sentence : "What will be the worst experience in my life ?" ?

Usually, the subject comes before the infinitive, like in "What will the king do ?" and not after : *"What will do the king ?".
The sentence "What will be the worst experience in my life" doesn't sound incorrect to me, but maybe I'm wrong.

Same thing with "would" :

2) "What would be the best job for me" seems to be a correct sentence, I believe. Yet, I do not think "What would be life without chocolate ?" is correct, or is it (I'd say "what would life be without chocolate ?").

3) Is there any rule explaining these issues ? Or am I mistaking ?

Many thanks in advance,
Hi, AV.

Your analysis is correct, as are your sentences.

I don't know if there's a rule. The only thing I notice here is that with the correct question forms, you may replace "what" with "that" and make a correct statement.

With the ones you've rejected, this test does not work. "That would be life without chocolate" is grammatical, but not idiomatic.

Well, I guess it's not exactly impossible. What would happen if all the chocolate trees died? (reply) I guess that would be life without chocolate!
So I guess it's not a very good test. (cacao)

With a question like "What would be a shame?" the replacement works, but you must make the statement first:

That would be a shame! (reply) What would be a shame?
AnonymousIs there any rule explaining these issues ?
This is covered by the rule that the subject and (first) verb are inverted in a question except when the subject is questioned, i.e., except when the question word (What? Which? or Who?) is the subject of the sentence. (It has nothing to do with the usage of will or would. do, have, can, might, should, and others all follow the same rule.)

The king will do this. [this is not the subject.] What will the king do?

This will be the best choice. [this is the subject.] What will be the best choice?

Summary: Don't invert for a question when the question word is the subject.