present perfect/follow up

In addition to regular English verbs, there are many irregular English verbs, which do not form the past participle with the ending ed. The English irregular verbs are related to the strong verbs of the German language. The following are examples of irregular English verbs. For example:

Bare Infinitive	Past Participle
begin	begun
find	found
go	gone
let	let
take	taken

The past participles of irregular English verbs are formed in an unpredictable manner, and must be memorized.Except for the irregularity of the past participle, the formation of the Present Perfect tense is the same for an irregular verb as for a regular verb. In both cases, the Simple Present of the auxiliary to have is followed by the past participle of the verb.

For instance, the irregular verb to take has the past participle taken. Thus, the Present Perfect of the irregular verb to take is conjugated as follows:

I have taken

you have taken

he has taken

she has taken

it has taken

we have taken

they have taken

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?