他们在非常非常小声的说话用英文怎么说

"Whispering" 或 "Speaking in a whisper" 是指在非常低声的情况下说话。这个词来源于英语中的 "whisper"，意思是 "低语"。

例句:

Can you please speak in a whisper? I don't want to wake up the baby. (请你说话小声点，我不想吵醒婴儿)
They were whispering secrets to each other. (他们在互相窃窃私语)
I couldn't hear what they were saying because they were whispering. (我听不清他们说什么，因为他们在说话很小声)