To talk about multiplication and multiples in Mandarin Chinese, you can use 倍
(bèi). This character works very much like “-times” or “-fold” in English, for
example in “ten times” or “two fold”. In other words, you can use 倍 to say
things like “A is twice as good as B” in everyday conversation.
There are three main ways to use 倍 to talk about multiples and multiplication
in Chinese. They use the characters 是 (shì), 有 (yǒu) and 比 (bǐ). Let's go
through them one by one.
Using 倍 with 是
The first 倍 structure we'll look at uses 是. The structure is:
[noun] 是 [noun] 的 [number] 倍
You can use this to say “[noun] is [number] times [noun]". Notice how Chinese
says the two nouns first, then the number and then 倍. English puts the number
with ‘times’ between the two nouns.
Let's have a look at some example sentences for this structure.
中国人口大约是英国人口的二十一倍。
Zhōngguó rénkǒu dàyuē shì Yīngguó rénkǒu de èrshíyī bèi.
The population of China is about twenty-one times that of the
UK.
米饭的热量是白菜的数倍。
Mǐfàn de rèliàng shì báicài de shù bèi.
Rice has several times more calories than cabbage.
氧原子的重量几乎是氢原子的十六倍。
Yǎng yuánzǐ de zhòngliàng jīhū shì qīng yuánzǐ de shíliù
bèi.
Oxygen atoms are almost sixteen times heavier than hydrogen
atoms.
日本人口是台湾人口的五倍左右。
Rìběn rénkǒu shì Táiwān rénkǒu de wǔ bèi zuǒyòu.
The population of Japan is about five times that of
Taiwan.
我现在的体重是过去的两倍。
Wǒ xiànzài de tǐzhòng shì guòqù de liǎng bèi.
My current weight is twice as high as before.
For giving straight multiplications of numbers, the structure is usually
re-arranged a little bit. It's still basically the same, though. Some examples:
二的四倍是八。
èr de sì bèi shì bā.
Two times four is eight.
三的三倍是九。
Sān de sān bèi shì jiǔ.
Three times three is nine.
You may also hear 二倍, e.g.:
二的二倍是四。
èr de èr bèi shì sì.
Two times two is four.
Note that there is a special way of saying “double”. Instead of 两倍 (which is
more versatile), you might also hear people say 双倍. This is to talk about
doubling things rather than “two times”. Some examples:
一角硬币的价值是五分的双倍。
Yījiǎo yìngbì de jiàzhí shì wǔ fēn de shuāng bèi.
Ten cent coins are worth twice as much as five cent
coins.
你加班我付你双倍工钱。
Nǐ jiābān wǒ fù nǐ shuāng bèi gōngqián.
I'll pay you double for working overtime.
双倍 is more for very fixed, definite ‘doubling’ of something.
Using 倍 with 有
The second 倍 structure we're looking at uses 有. The structure is very similar
to the first one:
[noun] 有 [noun] 的 [number] 倍
This structure is identical to the one above, but 是 is swapped for 有. Whether
to use 是 or 有 depends, quite intuitively, on whether something is or
has a quality that's a number of times something else. Bear in mind
that in most situations the 是 structure is probably the better choice. Let's
have a look at some example sentences:
光速有声速的八十八万多倍。
Guāngsù yǒu shēngsù de bāshíbā wàn duō bèi.
The speed of light is more than eighty-eight thousand times the
speed of sound.
他们国家的物价有我们国家的两倍。
Tāmen guójiā de wùjià yǒu wǒmen guójiā de liǎng bèi.
Commodity prices in their country are twice as high as in
ours.
Each of the above sentences could just as well be expressed with 是 instead of
有. Also be prepared for some variations on these structures, such as:
法定假日加班有三倍的工资。
Fǎdìng jiàrì jiābān yǒusān bèi de gōngzī.
According to law, holiday overtime pay must be three times
higher.
我们的投资数额有好几倍的差距。
Wǒmen de tóuzī shù'é yǒu hǎojǐ bèi de chājù.
The amount we invest differs by several times.*
(If anyone can think how to
phrase this nicely in English, please share it in the comments!)
Using 倍 with 比
The final 倍 structure is very different to the previous two. It uses 比, and
its meaning is different in an important way. Let's look at the structure first:
[noun] 比 [noun] [adjective] [number] 倍
It looks very similar to the 是 and 有 structures described above. However,
when you use 倍 with 比 like this, the multiplication is one time more.
That means that if you use 一倍 in this structure, you're doubling the
amount. If you use 两倍 in this structure, you're tripling the amount.
In other words, rather than just using the number as a multiple as in the 是 and
有 structures, the 比 structure adds that many multiples on to the
quantity. That is, when you use the 比 structure, you also include the original
quantity.
If you're confused, looking at these example sentences should help. To try and
make this clearer, each example is given twice, once with the 是 structure and
once with the 比 structure.
蓝箱子比红箱子重一倍。
Lán xiāngzi bǐ hóng xiāngzi zhòng yī bèi.
蓝箱子的重量是红箱子的两倍。
Lán xiāngzi de zhòngliàng shì hóng xiāngzi de liǎng bèi.
The blue box is twice as heavy as the red box.
他们的人数比我们多两倍。
Tāmen de rénshù bǐ wǒmen duō liǎng bèi.
他们的人数是我们的三倍。
Tāmen de rénshù shì wǒmen de sān bèi.
There are three times as many of them as us.
这个城市的人口比那个城市的多两倍。
Zhège chéngshì de rénkǒu bǐ nàgè chéngshì de duō liǎng
bèi.
这个城市的人口是那个城市的三倍。
Zhège chéngshì de rénkǒu shì nàgè chéngshì de sān bèi.
This city's population is three times that city's.
Remember that you can always use the 是 or 有 structure to keep things clear, as
they work the same as in English. The 比 structure is common, though, so it's
important to understand it.