The document discusses the present perfect tense in English. It explains that the present perfect is used to describe actions that began in the past and continue in the present, or actions that occurred over a period of time extending to the present. It provides the structure of the present perfect and examples using auxiliary verbs like "have" and "has" along with past participles. It also discusses the uses of words like "just", "already", "yet", and "since" with the present perfect.

1. Present perfect.
Just, already, yet and since.

2. What’s the use of present perfect?
● When an action started in the past and continues to the present.
● When an action happened during a time period that has not finished yet.
● When the action is more important than the time.

3. What the structure of present perfect is?
● Aff: Subject + Auxiliary* + verb** + complement.
● Neg: Subject + Auxiliary* + not + verb** + complement.
● Quest: Auxiliary* + subject + verb** + complement + ?.
*: Have (I/You/We/They)
Has (He/She/It)
**: Past participle.

4. Examples
I have been in London.
He has not cleaned the window yet.
I have already paid that debt.
You have not cooked the breakfast.
She has played piano for 10 years.
Have you made the bed?

5. Just
It is used to express than an action was done in a short time ago or in a recently past.
Jane has just cooked a cake. Would you like some?
We have just bought a house.
“just” always goes between the auxiliary and the verb in past participle.

6. For
We use the expression “For” to talk about how much time an action is taking.
● I have worked at the school for 3 years
● I have played soccer for 9 years.
The word “For” goes always before mentioning the time that the action is taking.

7. Already
It is used in affirmative sentences to say that the action was done.
● I have already written the article.
● I have already shown you the slides.
The word “already” always goes between the auxiliary and the verb.

8. Yet
It is used in question to ask if an action was done and in negative sentences to say that an
action wasn’t done, and it always goes at the end of the sentence.
● Have you read it yet?
● No, I haven’t read it yet.

9. Since
We use the expression “For” to talk about the exact time in which an action started.
● I have started to work since 2001.
● She has not had holidays since last summer.
“Since” always goes before mentioning the exact time