1. Present Continuous
2. Present Continuous
3. Present Perfect Continuous
4. Present Simple
5. Present Simple
1. The Thames is flowing through London. - Present Continuous
2. How often do you go to the dentist? - Present Simple
3. It is raining for several days - Present Continuous
4. Tom is writing a letter to his parents now. - Present Continuous
5. How long have you been smoking? - Present Perfect Continuous