This grammar exercise is meant for students of classes 9 and 10. It tests their ability to use different tense forms correctly.

Class 10 English grammar worksheets

Fill in the blanks with an appropriate verb form.

We still don’t …………1……………. whether life …………..2……………. on other planets. But if it ………….3……………., it’s most likely to be found on a planet that ……………4………… liquid water. That is because water ……………5…………… essential to life on Earth. Now, astronomers ……………6……………. a distant planet that could have water. That, in turn, …………….7……………. the possibility of extraterrestrial life.

1. a) know; b) knew; c) known; d) knowing
2. a) is existing; b) exists; c) exist; d) existed
3. a) does; b) is; c) has; d) did
4. a) is; b) has; c) have; d) had
5. a) was; b) is; c) has; d) will be
6. a) discovered; b) has discovered; c) had discovered; d) have discovered
7. a) raise; b) raises; c) raised; d) raising

Answers

We still don’t know whether life exists on other planets. But if it does, it’s most likely to be found on a planet that has liquid water. That is because water is essential to life on Earth. Now, astronomers have discovered a distant planet that could have water. That, in turn, raises the possibility of extraterrestrial life.