But Callum does say 'sorry' which is polite when we're declining an invitation.

但是Callum确实有道歉，这在道歉的时候是非常有礼貌的。

Another way of politely declining an invitation or saying no is to be tentative.

礼貌地拒绝邀请或拒绝的另一种方法是表现得犹豫不决。

'I'd like to but I'm actually going to watch TV' is not a good way to decline an invitation!

“我愿意去但是我得看电视”可不是拒绝邀请的好方式。

It seemed to me a little ungracious to decline an invitation of that sort, and I ascribed his refusal to lack of money.

我觉得拒绝这种邀请有些太不礼貌了。我向她解释，他是因为没有钱才拒绝的。

You might hear this in British English, but in the US don't use this to decline an invitation.

你可能会在英式英语中听到这个， 但在美国不要用这个来拒绝邀请。

This expression is often used in more formal situations when you need to decline an invitation or a request from someone important like your boss or another colleague.

这个表达方式通常用在更加正式的场合，当你需要拒绝来自于对你而言重要的人，比如说你的老板或者是同事的邀请或者是要求。

In general, if you decline an invitation to a bigger or a more important event, you will probably take longer to explain why you can't come and to show how much you'd like to come if only you could.

总的来说，假如你是拒绝参加某种相对较大的场合，你也许会花更长的时间来解释为什么你不但能到场，并且表现出如果可以的话你又是多么希望参加。