Here's how to fill in the blanks with the correct tense forms:

14. I **am digging** a big hole in my garden to plant a tree.
15. David and Ann **have been talking** on the phone for hours.
16. Olivia’s car **has broken** down today.
17. Your English **has improved** very much lately.
18. Walter and you **have walked** from work. So you must be tired.
19. A journalist **is writing** an interesting report about Education.
20. Thomas **has been driving** this old car since 2016.