очень
1. l'd rather you discuss/have discussed/had discussed installing new software with me before placing the order for it.
2. Were we to know/Should we have known/ Had we known how effective the program was, we would have installed it long ago.
3. I don't know if he comes/will come/should come to work tomorrow; he changed his schedule.
4. It's high time we will do/did/do something about the decline in the standard of literacy.
5. What if/Even if/Only if we don't have the latest data, we can still discuss the changes to the sales projections at the meeting.