Present Perfect: Questions- Negative Statements & Tag Questions

6. Questions and negative statements
As is the case with other English tenses, questions and negative statements in the Present Perfect are formed using the auxiliary. In the case of the Present Perfect, the auxiliary is have or has.

a. Questions
In order to form a question, the auxiliary is placed before the subject of the verb. For example:

Affirmative Statement	Question
I have worked.	Have I worked?
You have worked.	Have you worked?
He has worked.	Has he worked?
She has worked.	Has she worked?
It has worked.	Has it worked?
We have worked.	Have we worked?
They have worked.	Have they worked?

b. Negative statements
In order to form a negative statement, the word not is placed after the auxiliary. For example:

Affirmative Statement	Negative Statement
I have worked.	I have not worked.
You have worked.	You have not worked.
He has worked.	He has not worked.
She has worked.	She has not worked.
It has worked.	It has not worked.
We have worked.	We have not worked.
They have worked.	They have not worked.

The following contractions are often used in spoken English:

Without Contractions	With Contractions
have not	haven't
has not	hasn't

c. Negative questions
In order to form a negative question, the auxiliary is placed before the subject, and the word not is placed after the subject. However, when contractions are used, the contracted form of not follows immediately after the auxiliary. For example:

Without Contractions	With Contractions
Have I not worked?	Haven't I worked?
Have you not worked?	Haven't you worked?
Has he not worked?	Hasn't he worked?
Has she not worked?	Hasn't she worked?
Has it not worked?	Hasn't it worked?
Have we not worked?	Haven't we worked?
Have they not worked?	Haven't they worked?

d. Tag questions
Tag questions are also formed using the auxiliary. In the following examples, the negative tag questions are underlined.

Affirmative Statement	Affirmative Statement with Tag Question
I have worked.	I have worked, haven't I?
You have worked.	You have worked, haven't you?
He has worked.	He has worked, hasn't he?
She has worked.	She has worked, hasn't she?
It has worked.	It has worked, hasn't it?
We have worked.	We have worked, haven't we?
They have worked.	They have worked, haven't they?

Exercise:
Following the model of the examples, rewrite the following affirmative statements as questions, negative statements, negative questions without contractions, negative questions with contractions, and affirmative statements followed by negative tag questions. 

For example:
      I have read this book.
      Have I read this book?
      I have not read this book.
      Have I not read this book?
      Haven't I read this book?
      I have read this book, haven't I?

      He has found the answer.
      Has he found the answer?
      He has not found the answer.
      Has he not found the answer?
      Hasn't he found the answer?
      He has found the answer, hasn't he? Answers: 
1. Have they eaten the cookies? They have not eaten the cookies. Have they not eaten the cookies? Haven't they eaten the cookies? They have eaten the cookies, haven't they? 

2. Has she told the truth? She has not told the truth. Has she not told the truth? Hasn't she told the truth? She has told the truth, hasn't she? 

3. Has he run fast? He has not run fast. Has he not run fast? Hasn't he run fast? He has run fast, hasn't he? 

4. Have we watered the plants? We have not watered the plants. Have we not watered the plants? Haven't we watered the plants? We have watered the plants, haven't we? 

5. Have you hurried? You have not hurried. Have you not hurried? Haven't you hurried? You have hurried, haven't you?