What's the difference between the following?
- It will really be great if you can pass the salsa over here.
- It would really be great if you could pass the salsa over here.
- If you move your chair a bit, we can all sit down.
- If you moved your chair a bit, we could all sit down.
From I have learnt in grammar books, the first conditional is used to express a real possibility, while the second conditional is used to express an imagined situation. Since I'm not imagining a situation, and this is a real situation, I would use the first conditional for #1 and #2.