打断别人的话时，使用礼貌和委婉的表达是非常重要的。以下是一些常用的英语表达方式：

1. 请求允许打断：

"May I say something？"

"Could I get a moment of your time？"

"I couldn't help but overhear. May I contribute？"

2. 表达歉意并请求打断：

"I'm sorry to interrupt, but..."

"Excuse me for the interruption, but..."

"I hate to butt in, but..."

3. 表达需要紧急打断：

"I'm sorry to bother you, but you're needed..."

"Excuse me, but there's an emergency."

4. 表达想要补充或澄清：

"That reminds me..."

"I believe there's a point I should make..."

"May I add something to what you've said？"

使用这些表达时，请确保你的语气和面部表情与你的话语相匹配，以传达出尊重和歉意。打断别人说话前最好先等待对方说完一句话或一段话，并表现出你对话题的兴趣和参与