I'm afraid I can't give you a definite reply now. 恐怕我現在無法給你一個明確的答復。
　　I can't make a decision right now. 我現在無法作出決定。
　　I just need some time to think it over. 我需要時間考慮考慮。
　　We are still a little unsure about the prospect, though. 不過，我們對于前景還是有點不能確定。
　　There are certain points that I'll have to consider very carefully. 有些問題我得慎重考慮。
　　That may well be so. I'm not sure. 很可能是這樣的。我不敢確定。
　　It all depends. 這得看情況而定。