To be honest, both sound perfectly fine. If I had to mark a difference between them, I would say that your second example sounds a bit more professional, like a question being proposed in an interview. Also, there is a mild difference in natural answers:
"What new features of C# have you used?"
In this case, you could honestly answer this question with ...
The example is grammatically correct as written.
These have the same basic meaning. Only the shade (Definition) of meaning is different.
Do I look good?
Do I not look good?
The first one is understood as a more "neutral" question.
The second one is understood to mean that the person asking believes the underlying statement is true: "I look ...
The structure is archaic, and of limited acceptability in the present day outside of very formal or literary usage, as with forgoing do-support in general:
Built you this?
I know not.
Judge him not.
Although do-support is attested all the way from Old English, its adoption in questions, imperatives, and negations accelerated in Early Modern ...
How to write a program in Pascal?
Is not a usual or optimal way to phrase a question. Better would be:
How do you write a program in Pascal?
How does one write a program in Pascal?
How does a person write a program in Pascal?
In short the verb "write" should have a subject. Various other constructions are posisble with much the same meaning, ...
Speech: How old is Steve?
The inversion with think:
How old do you think Steve is?
The inversion in the question is for the verb think, not be.
The car is really very old.
Why do you think the car is very old?
The question concerns another verb and not the statement: the car is very old.
Compare: Is the car very old? That takes the inversion.
The first example you gave is in the correct form however for clarity the "How" should be removed in the second example. However, I am not sure what your context is and there is a third form.
Can is a modal verb they provide additional information about the function of the main verb that follows it.
Would you mind telling us how we can improve XXX? is ...
The sentence posted is ungrammatical, because of the word sequence and the use of the two auxiliary words "does" and "should".
There are two possible questions being asked:
At what time should she come to school on Saturday?
At what time does she come to school on Saturday?
Notice the inversion of "she should" to "should she" when phrased as a ...
One can indeed use a contraction in question:
Why don't you do it today?
But "you're" is a contraction of "you are" not of "are you " so it does not work in sentence b) from the question, which expands to:
Why you are trying so hard?
which is not really grammatical, and certainly does not carry the same meaning as sentence a).
"you're" can be used ...
you're is generally a contraction of "you are", so saying "why you are trying so hard?" would not sound totally correct in this instance. In general though there's no particular reason to not use a contraction in a question.
However, if formulated slightly differently it would sound idiomatic. Consider "You have to ask yourself why you're trying so hard".
I'd understand you, but since I already know that August is a month, there is a bit of duplication. You can say,
Will you stay open all through August?
Or . . . if you stay open the entire month of August.
"throughout" is alternative to "all through"
In what country can Mount Fuji be found?
As Kim points out, the original question is explicitly asking for a country. There is no context that implicitly asks for a country, so the question must use the word "country". If the question were changed to "Where", someone could answer "Honshu" or "Asia" or "Earth", instead of "Japan".
It is usually possible ...