Man: Where are you? 
Woman: I am working inside. I am writing a letter to my friend. I am telling him about my life and my new job. 
Man: Are you using the computer? 
Woman: I am not using the computer because I like to hand-write letters. My hand is getting tired though.
Man: Where is Mary? 
Woman: Mary is cooking in the kitchen. She is chopping up some vegetables because she is making a vegetable soup. 
Man: How is she making it? 
Woman: She is reading a recipe and following the instructions inside. She is enjoying herself.
Man: What is Bob doing? 
Woman: Bob is working on his car. He is giving it a tune up. He is changing the oil and checking all the parts of the cars. 
Man: But, he is not working? He is just standing there! 
Woman: He is taking his time because he wants to do the job right. He is listening to the radio as he works.
Man: Where are the twins? 
Woman: They are playing outside. They are playing soccer with their friends. They are using the front lawn as a soccer pitch. 
Man: Are they having fun? 
Woman: They are having a lot of fun. They are exercising so they are burning lots of energy. I think they are trying to lose weight.
Present Continuous 
Point 1 : We use the present continuous for actions that start and finish within a time frame. We often say the action is happening now.
Point 2 : We use the present simple tense for an action that is repeating or ongoing. We use the present continuous if the action will end at some time.
Point 4 : We often use the present continuous for plans in the future, especially if the action is known or anticipated by other people.