Present perfect tense?

The present perfect tense is formed by using the auxiliary verb "have" or "has" followed by the past participle of the main verb. It is used to indicate actions or events that have been completed at some point in the past but have relevance to the present moment. For example:

- I have finished my homework.
- She has traveled to Europe.
- They have eaten dinner.

Present Perfect Tense

The present perfect tense describes actions or states that began in the past and continue into the present moment. It is used in the following situations:

To indicate a completed action that has effects or relevance in the present:
- I have lost my keys. (I can't find them now.)
- She has finished her homework. (It's done now.)

To express an action that started in the past and still continues in the present:
- I have worked here for five years. (I still work here.)
- She has been living in this house for 10 years. (She still lives there.)

To indicate an action or experience that has happened at least once in the past:
- I have seen that movie twice.
- He has traveled to many countries.

Formation:

The present perfect tense is formed using the present tense of "have" or "has" followed by the past participle of the main verb.

- Singular: have + past participle
- Plural: has + past participle

Examples:

- I have eaten breakfast.
- She has bought a new car.
- They have gone to the park.

Contractions:

"Have" and "has" can be contracted to "ve" and "'s":

- I've eaten breakfast.
- She's bought a new car.

Interrogative and Negative Forms:

Interrogative:
- Have I eaten breakfast?
- Has she bought a new car?

Negative:
- I have not eaten breakfast (I haven't eaten breakfast).
- She has not bought a new car (She hasn't bought a new car).