1. Regarding payment , most major credit cards are acceptable
⇒As far as payment is concerned, most major credit cards are acceptable.
2. There were not nearly as many people there as i had expected
⇒There were far fewer people there than I had expected
3. We could not have succeeded without my father's money
⇒If it hadn't been for my father's money, we could not have succeeded
4. The guest didn't tell us why he had behaved so strangely at the ceremony
⇒The reason why he had behaved so strangely at the ceremony was unknown