THE PRESENT PERFECT TENSE

1. Use :

The English Present Perfect tense is used to express actions which have just or already been completed at the time of speaking or writing.
--> I have done the work.
--> She has answered half the questions.

In the first example, the use of the Present Perfect tense emphasizes the fact that, at the time of speaking or writing, the work has already been completed. In the second example, the use of the Present Perfect indicates that, at the time of speaking or writing, half the questions have been answered.

This tense epresses the very recent past:
--> They've just left.

It also tells of a state or situation which has started in the past and is continuing up to now:
--> I have lived there for a long time. (I am still living there.)

The event may be a finished state or activity but the period of time in which it has taken place is not finished:
--> I have written a letter this morning. (the letter is finished and it is still morning)

It tells about an event with a present result :
--> I have lost my keys.

  2. Formation of the present perfect: Regular verbs
The Present Perfect tense of any English verb is formed from the Simple Present of the auxiliary to have, followed by what is generally referred to as the past participle of the verb.

Most English verbs form the past participle in a regular, predictable manner. These verbs are commonly referred to as regular verbs.

The past participle of a regular English verb is formed by adding the ending ed to the bare infinitive of the verb. For instance, the past participle of the verb to work is worked.

Thus, the Present Perfect tense of the verb to work is conjugated as follows:

I have worked

you have worked

he has worked

she has worked

it has worked

we have worked

they have worked

The following contractions are often used in spoken English:

Without Contractions	With Contractions
I have	I've
you have	you've
he has	he's
she has	she's
it has	it's
we have	we've
they have	they've

It should be noted that the contractions for he has, she has and it has are the same as the contractions for he is, she is and it is.


  3. Spelling rules for adding ed to form the past participle
Some regular verbs change their spelling when the ending ed is added to form the past participle.

a. Verbs ending in a silent e
When a regular verb ends in a silent e, only the letter d must be added in order to form the past participle. For example:

Infinitive	Past Participle
to close	closed
to move	moved
to please	pleased
to receive	received

b. Verbs ending in y
When a regular verb ends in y immediately preceded by a consonant, the y is changed to i before the ending ed is added. For example:

Infinitive	Past Participle
to study	studied
to rely	relied
to carry	carried

However, when a regular verb ends in y immediately preceded by a vowel, the y is not changed before the ending ed is added. For example:

Infinitive	Past Participle
to play	played
to convey	conveyed
to enjoy	enjoyed

c. Verbs ending in a single consonant preceded by a single vowel
The rules concerning the doubling of final consonants which apply when adding the ending ing to form the present participle also apply when adding the ending ed to form the past participle.

Thus, when a one-syllable verb ends in a single consonant other than w, x or y immediately preceded by a single vowel, the final consonant must be doubled before the ending ed is added to form the past participle. In the following examples, the consonants which have been doubled are underlined. For example:

Infinitive	Past Participle
to rub	rubbed
to trim	trimmed
to plan	planned
to stop	stopped

When a verb of more than one syllable ends in a single consonant other than w, x or y immediately preceded by a single vowel, the final consonant is doubled before the ending ed only when the last syllable of the verb is pronounced with the heaviest stress. In the following examples, the syllables pronounced with the heaviest stress are underlined. For example:

Infinitive	Past Participle
to control	controlled
to infer	inferred
to occur	occurred
to permit	permitted
to fasten	fastened
to order	ordered
to focus	focused
to limit	limited

In the first four examples, the last syllable of the verb is pronounced with the heaviest stress, and the final consonant is doubled before ed is added. In the last four examples, the first syllable of the verb is pronounced with the heaviest stress, and the final consonant is not doubled before ed is added.

The final consonants w, x and y are never doubled when the ending ed is added. For example:

Infinitive	Past Participle
to follow	followed
to box	boxed
to portray	portrayed

It should also be noted that final consonants immediately preceded by two vowels are not doubled when the ending ed is added. For example:

Infinitive	Past Participle
to greet	greeted
to rain	rained
to soak	soaked
to treat	treated

  4. Pronunciation of the ed ending
The ending ed is usually not pronounced as a separate syllable. For instance, in each of the following examples, both the bare infinitive and the past participle consist of one syllable. For example:

Bare Infinitive	Past Participle
puff	puffed
work	worked
miss	missed
watch	watched

However, when the ending ed is added to verbs which end in d or t, the ed ending of the past participle is pronounced as a separate syllable. The reason for this is that the sounds of d and t are so similar to the sound of the ed ending, that the ending must be pronounced as a separate syllable in order to be heard clearly.

In each of the following examples, the bare infinitive consists of one syllable; whereas the past participle consists of two syllables. For example:

Bare Infinitive	Past Participle
add	added
land	landed
hunt	hunted
wait	waited

Similarly, when d is added to verbs ending in a silent e preceded by d or t, the final ed of the past participle is pronounced as a separate syllable. In each of the following examples, the bare infinitive consists of one syllable; whereas the past participle consists of two syllables. For example:

Bare Infinitive	Past Participle
fade	faded
glide	glided
cite	cited
note	noted

  5. Formation of the present perfect: Irregular verbs
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?