QUESTION

Question Yes/No

Definition
Yes or no questions are questions whose expected answer is either "yes" or "no".

How to form yes-no questions
In English, a special word order (Verb Subject Object) is used to form yes-no questions.
Examples:

Affirmative	Yes or No Question
They are American	Are they American?
She is nice	Is she nice?

The rules

1. If the main verb of the sentence is "to be", simply invert the subject and the verb to be:
Examples:

• They are Germany. — Are they Germany?
• They are nice. — Are they nice?

2. If the sentence includes a main verb and another or other helping (auxiliary) verb(s), invert the subject and the (first) helping (auxiliary) verb.
Examples:

• They are visiting Paris. — Are they visiting Paris?
• She has done the housework. — Has she done the housework
• Nancy has been working all night long. — Has Nancy been working all night long?
• He will be reading the book. — Will he be reading the book?

3. If the sentence includes a verb which is not the verb "to be" and doesn't include a helping (auxiliary) verb, the transformation is more complex.
a. If the verb is in the present tense, add either do or does and put the main verb in its base form:

• do if the subject is the first person singular, second person singular, first person plural, second person plural and third person plural (I, you, we, they)
  Examples:
  I like apples. — Do you like apples?
  They go to a high school. — Do they go to a high school?
• does if the subject is the third person singular (he, she, it).
  Examples:
  Nancy reads a lot. — Does Nancy read a lot?
  He hates basketball. — Does he hate basketball?

b. If the verb is in the past tense, add did and put the main verb in its base form:
Examples:

• He discovered the truth. — Did he discover the truth?
• She wrote a nice essay. — Did she write a nice essay?
• They did the homework. — Did they do the homework?

Wh-Questions

Definition
Wh-questions are questions that begin with one of the eight “wh ” words: who, whose, what, when, which, why, where and how. Questions formed with “wh ” words ask about the word or phrase the “wh ” word replaces. Who replaces pronouns and the names of people. When the question word is the subject, the word order doesn't change:

“Columbus discovered America in 1492.”
 “Who discovered America in 1492?”

Question words

Question words are also called wh questions because they include the letters 'W' and 'H'.

Question words	Meaning	Examples
who	Person	Who's that? That's Nancy.
where	Place	Where do you live? In Boston
why	reason	Why do you sleep early? Because I've got to get up early
when	time	When do you go to work? At 7:00
how	Manner	How do you go? By car
what	object, idea or action	What do you do? I am an engineer
which	Choice	Which one do you prefer? The red one.
whose	possession	Whose is this book? It's Alan's.
whom	object of the verb	Whom did you meet? I met the manager.
what kind	Description	What kind of music do you like? I like quiet songs
what time	Time	What time did you come home?
how many	quantity (countable)	How many students are there? There are twenty.
how much	amount, price (uncountable)	How much time have we got? Ten minutes
how long	duration, length	How long did you stay in that hotel? For two weeks.
how often	Frequency	How often do you go to the gym? Twice a week.
how far	Distance	How far is your school? It's one mile far.
how old	Age	How old are you? I'm 16.
how come	reason	How come I didn't see you at the party?

Asking questions

1.If you ask about the subject of the sentence, simply add the question word at the beginning:

Example:
James writes good poems. — Who writes good poems?

2.If you ask about the predicate of the sentence (the part of a sentence which contains the verb and gives information about the subject), there are three options:

• ·         If there is a helping (auxiliary) verb that precedes the main verb ( for example: can, is, are, was, were, will, would...), add the question word and invert the subject and the helping (auxiliary) verb.

Examples:
He can speak Chinese. — What can he speak?
They are leaving tonight. — When are they leaving?

• ·         If you ask about the predicate and there is no helping (auxiliary) verb and the verb is "to be", simply add the question verb and invert the subject and the verb.

Example:
The play was interesting. — How was the play?

• ·         If there is no helping (auxiliary) verb in the the predicate and the main verb is not "to be", add the auxiliary "do" in the appropriate form.

Examples:
They go to the movies every Saturday. — Where do they go every Saturday?
He wakes up early. — When does he wake up?
They sent a letter. — What did they send?

Question tag

Definition
A tag question is a question we can add to the end of a statement.

The basic rules for forming the two-word tag questions are as follows:
* the subject in the statement matches the subject in the tag
* the auxiliary verb or verb to be in the statement matches the verb used in the  
   tag
* if the statement is positive, the tag is usually negative and vice versa

Positive/negative
If the main part of the sentence is positive, the question tag is negative ….

• He’s a doctor, isn’t he?
• You work in a bank, don’t you?

... and if the main part of the sentence is negative, the question tag is positive.

• You haven’t met him, have you?
• She isn’t coming, is she?

With auxiliary verbs
The question tag uses the same verb as the main part of the sentence. If this is an auxiliary verb (‘have’, ‘be’) then the question tag is made with the auxiliary verb.

• They’ve gone away for a few days, haven’t they?
• They weren’t here, were they?
• He had met him before, hadn’t he?
• This isn’t working, is it?

Without auxiliary verbs
If the main part of the sentence doesn’t have an auxiliary verb, the question tag uses an appropriate form of ‘do’.

• I said that, didn’t I?
• You don’t recognise me, do you?
• She eats meat, doesn’t she?

With modal verbs
If there is a modal verb in the main part of the sentence the question tag uses the same modal verb.

• They couldn’t hear me, could they?
• You won’t tell anyone, will you?

With ‘I am’
Be careful with question tags with sentences that start ‘I am’. The question tag for ‘I am’ is ‘aren’t I?’

• I’m the fastest, aren’t I?

Source :

http://dictionary.cambridge.org/grammar/british-grammar/questions-yes-no-questions-are-you-feeling-cold

http://en.wikipedia.org/wiki/Tag_question

http://www2.gsu.edu/~eslhpb/grammar/lecture_10/wh_questions.html