你有几个妹妹？(Nǐ yǒu jǐ gè mèimei?)
How many younger sisters do you have?
你家有几口人？(Nǐ jiā yǒu jǐ kǒu rén?)
How many people are there in your family?
你的孩子几岁了？(Nǐ de háizi jǐ suì le?)
How old is your child?
你们学校有多少个学生？(Nǐmen xuéxiào yǒu duōshǎo gè xuéshēng?)
How many students are there in your school?
中国有多少个人？(Zhōngguó yǒu duōshǎo gèrén?)
How many people are there in China?
The measure word following 多少 could be omitted. But there must be a measure word after 几.
你们公司有多少（个）人？(Nǐmen gōngsī yǒu duōshǎo (gè) rén?)
How many people are there in your company?
中文有多少（个）汉字？(Zhōngwén yǒu duōshǎo (gè) hànzì?)
How many Chinese characters are there in Chinese?
你们几个人吃饭？(Nǐmen jǐ gèrén chīfàn?)
How many of you eat?
你早上喝了几杯咖啡？(Nǐ zǎoshang hēle jǐ bēi kāfēi?)
How many cups of coffee did you drink in the morning?
多少 can also be used to inquire about prices, usually in the sentence pattern “……多少钱？”. Note that in this pattern, we use 多少 without measure words. The measure word cannot be omitted when using 几 in this case.
这件衣服多少钱？(Zhè jiàn yīfu duōshǎo qián?)
How much is this shirt?
这个苹果几元钱？(Zhège píngguǒ jǐ yuán qián?)
How much is this apple?
多少 can be used independently without classifier and noun following it, but 几 cannot.
水果买了多少？(Shuǐguǒ mǎile duōshǎo?)
How many fruits did you buy?
酒喝了多少？(Jiǔ hēle duōshǎo?)
How much wine did you drink?
人来了多少？(Rén láile duōshǎo?)
How many people are here?
”几” can be used to inquire about a point in time, usually in the sentence patterns such as “几点” “几月几号” and “星期几”.
今天是几月几号？(Jīntiān shì jǐ yuè jǐ hào?) What is the date today?
我们几点去学校？(Wǒmen jǐ diǎn qù xuéxiào?) What time do we go to school?
学校星期几考试？(Xuéxiào xīngqī jǐ kǎoshì?) What day is the school exam?
”多少” can be used to inquire about one’s phone number, but “几” couldn’t use in this case.
你的电话号码是多少？(Nǐ de diànhuà hàomǎ shì duōshǎo?) What is your phone number?
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