1. The earth moves around the sun.

2. The earth moves round the sun.
(Which one is grammatical? Are both OK? Which one is commonly used?)

3. When does the movie come out in DVD?
4. When will the movie come out in DVD?
(Which one is correct?)

5. I'm not sure if she calls me again tomorrow.
6. I'm not sure if she will call me again tomorrow.
(Which one is grammatical?)

1 answer

1 is grammatical; 2 is not.

Both 3 and 4 are correct.

5. is wrong; 5 is right.