The variation in word-order can best be understood by changing declarative sentences to interrogative sentences and observing the shifting which must take place to accomplish the change.The exact nature of such shifting depends upon the verb in the declarative sentence.
1. If the verb is a verb phrase, the sentence is changed to a question by shifting the auxiliary verb to the beginning of the sentence.
Copy all examples - -
Examples: He was studying . Was he studying?
She has refused the offer. Has she refused the offer?
He had been sick. Had he been sick?
2. If the verb is a single word, it usually is first expanded to a verb phrase containing a form of the verb to do as the auxiliary, and the auxiliary verb is then shifted as noted above.
Examples: His sister teaches (= does teach). Does his sister teach?
The team lost (= did lose) the game. Did the team lose the game?
He became (= did become) a dovtor.
Did he become a doctor?
3. The verb ‘to be’ is an exception to this last rule.
Examples: He is a chef. Is he a chef?
She was unhappy. Was she unhappy?
Note that these forms of the verb to be cannot be expanded to verb phrases without extreme awkwardness. Only the first auxiliary is moved to the beginning of the sentence if the phrase contains two or more auxiliaries.
Example: They will be working. Will they be working?
QUESTION ASKED BY VARIATION IN TONE OF VOICE OR WORD-ORDER
Variation in Tone of Voice Alone
A sentence may have the same word-order that a similar declarative sentence would have and yet ask a question by means of the tone of voice used in speaking it.
This "questioning tone of voice" in writing would be indicated by the question mark [ ? ] at the end.
Compare the following interrogative sentences with the declarative sentences given as examples above:
He is singing? The car hit the pole? She is a typist?
Variation in Word-Order
Most interrogative sentences which do not contain interrogative words ask questions by means of a shift in word-order.