Exercise 3. Use the Present Continuous or the Present Indefinite.
1. When the water particle (to expose) to cold air, they (to crystallize) into snow.
2. I (to write) in response to your request for advice or choosing a career.
3. I (to enclose) my curriculum vitae together with three references. Do not hesitate to contact me if you (to require) any further information.
4. Russia (to enjoy) a tourist boom that has become increasingly important to the country’s economy.
5. Now my parents (to consider) leaving the city where they (to live) and moving to the countryside.
6. He only just (to recover) from the operation. He (to spend) most of his time in the garden.
7. How you (to get on) with your dissertation? — At the moment I (to write) the first chapter.
8. Frank is an excellent student. He (to speak) three foreign languages fluently.
9. Unfortunately, my sisters (not to get on) well. They always (to argue).
10. We must go now. It (to get) late.
11. The little girl has just fallen down and cut her elbow. It still (to bleed).
12. Steve (to do) his homework before supper. Has he finished his homework? — No, he still (to do) it.
13. She wants to but a BMW, but first she must learn how to drive, so she (to take) driving lessons.
14. You can borrow my computer. I (to use) it a great deal, but I (not to use) it at this moment.
15. My father is a very hard worker. He often (to work) until midnight. It’s 11.30 p.m. now and he still (to work).

1. When the water particle is exposed to cold air, they crystallize into snow. (Present Indefinite)
Explanation: We use the Present Indefinite tense to talk about general truths or habitual actions. In this sentence, it is a general truth that when water particles are exposed to cold air, they always crystallize into snow.

2. I am writing in response to your request for advice or choosing a career. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of writing is happening now.

3. I am enclosing my curriculum vitae together with three references. Do not hesitate to contact me if you require any further information. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of enclosing is happening now.

4. Russia is enjoying a tourist boom that has become increasingly important to the country’s economy. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of enjoying the tourist boom is happening now.

5. Now my parents are considering leaving the city where they live and moving to the countryside. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of considering leaving and moving is happening now.

6. He has only just recovered from the operation. He is spending most of his time in the garden. (Present Indefinite)
Explanation: We use the Present Indefinite tense to talk about general truths or habitual actions. In this sentence, it is a general truth that he always spends most of his time in the garden.

7. How are you getting on with your dissertation? - At the moment, I am writing the first chapter. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of writing the first chapter is happening now.

8. Frank is an excellent student. He speaks three foreign languages fluently. (Present Indefinite)
Explanation: We use the Present Indefinite tense to talk about general truths or habitual actions. In this sentence, it is a general truth that Frank always speaks three foreign languages fluently.

9. Unfortunately, my sisters are not getting on well. They always argue. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of arguing is happening now.

10. We must go now. It is getting late. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of getting late is happening now.

11. The little girl has just fallen down and cut her elbow. It is still bleeding. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of bleeding is happening now.

12. Steve does his homework before supper. Has he finished his homework? - No, he is still doing it. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of doing his homework is happening now.

13. She wants to buy a BMW, but first she must learn how to drive, so she is taking driving lessons. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of taking driving lessons is happening now.

14. You can borrow my computer. I use it a great deal, but I am not using it at this moment. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of using the computer is not happening at this moment.

15. My father is a very hard worker. He often works until midnight. It’s 11.30 p.m. now, and he is still working. (Present Continuous)
Explanation: We use the Present Continuous tense to talk about actions happening at the moment of speaking or around now. In this sentence, the action of working is happening now.