The present perfect

1. Uses

1.1. Describe an experiencie

1.2. Describe a change over period of time

1.3. Describe accomplishments

1.4. A continuing action that started in the past

2. Affirmative estructure

2.1. Subject + have/has + past participle + object

2.2. I have travalled the world

3. Negative estructure

3.1. Subject ´+ have/has + not + past participle + object

3.2. House prices have increased a lot

4. Interrogative estructure

4.1. Have/has + subject + past participle + object?

4.2. We have been a relationship for 3 months