V. The Present Continuous vs. The Present Indefinite.

The Present Continuous is used to denote:	The Present Indefinite is used to denote:
something that is happening at or around the time of speaking; I am reading Harry Potter.	things in general or things that happen repeatedly; I read a lot.
temporary situations; You are working hard today. - Yes. I have got a lot to do.	permanent situations; John works hard most of the time.
annoying or surprising habits; My neighbour is always playing the piano.	habits, character traits, abilities; She plays the piano.
personal arrangements; What time are you leaving tomorrow?	timetables, programmes, etc. What time does the train leave?

The Present Perfect

I. The Formation

All the forms of the Present Perfect are analytic. They are formed by means of the Present Indefinite of the auxiliary ''have'' and Participle II of the notional verb.

In the interrogative form the auxiliary comes before the subject, Participle II following it.

In the negative the corresponding negative forms of ''have'' are used, Participle II following them.

• I have spoken.

• Have you spoken?

• I have not spoken.

• Haven't I spoken?

• Have I not spoken?

II. The Use

The Present Perfect has three distinct uses.

1) The Present Perfect is used to express an action already completed before the present situation but connected with the present situation in its consequences (Present Perfect Exclusive). We can often change a present perfect sentence into a present sentence with a similar meaning.

• I have torn the paper in two (=The paper is torn in two).

• I have come (=I am here).

• Have you read the Bible? (=Do you know the Bible?)

Note 1: The Present Perfect is frequently used with the adverbs 'just, already, yet, so far, recently, lately, ever, often, seldom, never, still, once, twice, three times'. Mind that we use already with the affirmative and yet with the negative and in questions.

Note 2: Present Perfect is often used when the time is not mentioned either because it is unknown or unimportant.

• I have milked a cow three times.

• He has bought a new car!

Note 3: Depending on the context, the Present Perfect of terminative verbs may lose its resultative character. This is the case when the context shows repeated actions. We can use the Present Perfect to say that something has happened several times up to the present.

• She has often opened the window and sat for hours looking out.

• I’ve written six letters since lunchtime.

• I’ve sometimes thought of moving to Australia.

• How often have you been in love in your life?

Note 4: As the Present Perfect expresses relevance to the present, we normally use it to announce news or to introduce a new topic of conversation. After announcing news, we usually use the Past Simple to give more details.

• Uncle George has crashed the car again. He ran into a tree in High Street.

• Joe has passed his exam. He got 87%.

• Oh, I’ve cut my finger! – How did it happen?

• - Pussy Cat, Pussy Cat, where have you been?

- I have been to London to look at the Queen.

- Pussy Cat, Pussy Cat, what did you see there?

- I saw a little mouse under her chair!

Note 4: The present perfect is often used in letters.

• I am sorry I haven't written before but I've been very busy lately as Tom has been away. We have carefully considered the report which you sent us on 26 April, and have decided to take the following action.

Note 5: We use the Present Perfect with other present tenses with report/comment verbs or phrases (guess, imagine, suppose, etc.). We also use it when commenting on the present result of something in the past (usually with appear, seem, sound, etc.).

• I reckon Gloria’s been held up in traffic. Do you suppose they have forgotten they’re meant to be here?

• He sounds as if he has run all the way here.

• It seems they’ve already decided without consulting us.

2) The Present Perfect is used in adverbial clauses of time and condition to denote an action completed before the definite moment in the future. The action of the subordinate clause will be accomplished before the action of the principal clause.

• I won't leave till you have answered me.

Note 1: Sometimes the Present Indefinite is found in this type of clauses in the same meaning of the verb. With durative verbs the Present Perfect is necessary. With terminative verbs the use of both forms is possible.

• I can tell you everything when I have tried the machine.

• Mother will stay at home until we return/have returned.

3) The Present Perfect is used for an action which lasts throughout an incomplete period, i.e. it began in the past and continued into the present (the Present Perfect Inclusive).

• He has been in the army for two years. (He is still in the army)

• It has been very cold lately but now it is getting warmer.

Note 1: Its use is compulsory with verbs which cannot be used in the Continuous form.

• I have loved her since she was a child.

Note 2: The Present Perfect is preferred to the Present Perfect Continuous in the negative sentences.

• It hasn't rained for two weeks. (cf. It has been raining for two weeks.)