Choose the right tense form. Nina has been learning/has learned English for 2 years. The birds have...

1. Nina has been learning English for 2 years. (Present Perfect Continuous)
2. The birds have already flown to the South. (Present Perfect)
3. They have known him for many years. (Present Perfect)
4. Mike has forgotten to learn the poem. (Present Perfect)
5. The children have been watching cartoons for 2 hours. (Present Perfect Continuous)
6. The train has just come. (Present Perfect)
7. We haven’t had a holiday for 5 years. (Present Perfect)
8. She has been teaching at this school for twenty years. (Present Perfect Continuous)
9. David has been painting in his studio since 10 o’clock. (Present Perfect Continuous)
10. Mary and Sam have been collecting stamps for 3 years. (Present Perfect Continuous)
11. Their parents have been friends since their childhood. (Present Perfect Continuous)
12. Dave has been a student for 2 years. (Present Perfect Continuous)

For each sentence, the correct tense form to use, whether Present Perfect Simple or Present Perfect Continuous, depends largely on the context of the action described – whether the focus is on the completion of the action or its duration and continuity. Here are the correct choices based on the examples provided:

1. Nina has been learning English for 2 years.

   • This tense is used to emphasize the duration of the activity (learning English).

2. The birds have already flown to the South.

   • This tense is used because the action (flying to the South) is completed.

3. They have known him for many years.

   • This tense is used for states or situations that are seen as permanent or for a long duration.

4. Mike has forgotten to learn the poem.

   • This tense is used because it refers to a single, complete action (forgetting).

5. The children have been watching cartoons for 2 hours.

   • This tense emphasizes the ongoing duration of the activity (watching cartoons).

6. The train has just come.

   • This tense is used because the action (the train arriving) is completed.

7. We haven’t had a holiday for 5 years.

   • This tense is used to talk about something that hasn’t happened over a period up until now.

8. She has been teaching at this school for twenty years.

   • This tense emphasizes the ongoing nature and duration of the job (teaching).

9. David has been painting in his studio since 10 o’clock.

   • This tense is used to emphasize the ongoing duration of the activity (painting).

10. Mary and Sam have been collecting stamps for 3 years.

    • This tense is used to emphasize the duration of the activity (collecting stamps).

11. Their parents have been friends since their childhood.

    • This tense is used for long-lasting relationships or states.

12. Dave has been a student for 2 years.

    • This tense is used to emphasize the duration of the state (being a student).

In summary, the Present Perfect Continuous is typically used to stress the continuity or duration of an ongoing action, while the Present Perfect Simple is more often used for completed actions or to state a fact that is true up until now.

Nina has been learning English for 2 years. The birds have already flown to the South. They have known him for many years. Mike has forgotten to learn the poem. The children have been watching cartoons for 2 hours. The train has just come. We haven’t had a holiday for 5 years. She has been teaching at this school for twenty years. David has been painting in his studio since 10 o’clock. Mary and Sam have been collecting stamps for 3 years. Their parents have been friends since their childhood. Dave has been a student for 2 years.