I can't say for certain off-hand.

　　我还不能马上说定。

　　off-hand直译过来就是：“不在手掌控制范围之内”，这个短语的正确意思是：“当即，立即”。因此，当美国人说"I can't say for certain off-hand."时，他/她要表达的意思就是:"I can't decide now."、"I can't make sure of it right now." 。

　　情景对白：

　　Shirley: Excuse me, have you decided who will be sent to attend the meeting?

　　雪莉：抱歉，您确定派谁参加会议了吗？

　　Boss: I can't say for certain off-hand. I will let you know when I have the decision.

　　老板：我还不能马上说定。等我有决定了就会通知你。

　　搭配句积累：

　　①When shall we start off?

　　我们什么时候出发？

　　②Shall we make it a deal now?

　　我们现在就成交？

　　③Will our meeting be put off?

　　我们的会议要推迟吗？

　　④Sir, when will you return? You need to sign some important documents.

　　老板，你什么时候回来？有些重要的文件需要你签字。

　　单词：

　　put off 推迟

　　The Association has put the event off until October.

　　协会已把这次活动推迟至10月。

　　If it should snow tomorrow, the meeting would be put off.

　　如果明天下雪的话，运动会就会推迟。

　　I always seem to put things off till the last minute.

　　我似乎总是把事情拖到最后一刻。