Most of Indonesian learners find difficulties in Expressing a Question. They do not know when to use questions words or other, say, particles, like do, does, did, have ,etc to construct a question. Here, Let me help you with it.
There are two types of questions In English, they are:
1. Yes/No Question, and
Yes-No Question is a question which has only two answers logically needed, they are: [yes] or [No].
This type of question is characterized by placing One Auxilliary in the beginning of a sentence.
Do you know me?
The word "DO" is one of auxilliaries in English. You can use, like; Does, did, have, has, will or others and "be" instead /do/. However, the use of each auzilliaries above depends on the type of sentence and tense being used.
For instance, you would like to give one a question about what he or she did in the night weekend.
Then you can say:
"Did you find my key last night?"
Here, you use /did/. It is because the event you are asking about is in the past. Therefore, you need two things to make a question [Yes-No Question].
First, The Point of Time [tenses].
Second, The construction.
Take notice that the construction here includes two things, they are:
a). Kind of Auxilliary you need.
b) Where Aux. will be placed.
Talking about Present Tense, you will find /Do/ and /Does/ In a form of Verbal sentence. When the subject is, say, /She/, you need /Does/ as the auxilliary then.
Wh-Question is question words which are prefixed by /Wh-/, like:
What (To ask about things - subject, object or complement)
Where (To ask about place - adverb of place)
Which (To ask about choice)
When (To ask about time)
Who (To ask about person - Subject Oriented)
Whom (To ask about person - Object Oriented)
Whose (To ask about Possession)
Why (To ask about Reason)
and also, How (To ask about Condition, method or manner).
When you use Wh-Question in your Question, you just place it in the beginning of the sentence. The use of Auxilliary depends on the kind of wh-question you use.
What is he doing?
The word /what/ above is to ask about a thing. In the example, it asks about duty, obligation, activity at a time of speaking (Present Progressive Tense). Then you need the be /is/. It is because /is/ is used by the subject of /he/ and the construction of Present Progressive Tense.
/Subject/ will be omitted when you use /Who/ in your question.
Who is speaking to him?
In the sentence above, the subject /he/ or /she/ or (may be - /it/) is omitted. Why? It is because, the Question word /who/ asks about Subject/Person/.
The be will be omitted when the sentence is expressed something happenned in the completely past time.
Who sold your car?
The word /sold/ is second verb or the past form verb. Here, we do not need a /be/.
As a conclusion, English Question takes close attention to:
1/ Type of Question
Have a nice day!