"几倍"用英语可以表达为"several times"或"multiple times"。例句如下：

这个数字是原来的几倍？ How many times greater is this number than the original?

这个价格比原来高几倍？ How many times higher is this price than the original?

来源：

"several"的意思是"几个；几个的"，例如：I have several books. (我有几本书。)

"times"的意思是"次数；倍数"，例如：The number is three times greater than the original. (这个数字是原来的三倍。)

因此，"几倍"用英语可以表达为"几个次数；几个倍数"，即"several times"或"multiple times"。