口 (kǒu) — mouth / measure word for mouths and bites

口 (kǒu)

The mouth, and a measure word used for mouthfuls, bites, sips, and by extension, the number of people in a family. 口 is one of the oldest and most frequently used Chinese characters.

Meanings

1. [noun] Mouth. The opening in the face used for eating and speaking.
2. [measure word] Classifier for bites, sips, or mouthfuls of food or drink.
3. [measure word] Classifier for people in a family unit.

What 口 counts

口 is used with:

• Food portions: 吃一口 (take a bite), 喝一口 (take a sip)
• Family members: 三口人 (three people / a family of three)
• Wells or pools: 一口井 (one well)
• Language ability: 说一口好汉语 (speak excellent Chinese)

Example Sentences

我只吃了一口。 Wǒ zhǐ chīle yī kǒu. I only took one bite.

你家有几口人？ Nǐ jiā yǒu jǐ kǒu rén? How many people are in your family?

我家有三口人。 Wǒ jiā yǒu sān kǒu rén. My family has three people.

喝一口水吧。 Hē yī kǒu shuǐ ba. Take a sip of water.

Collocations

Common Learner Mistake

When talking about family size, Chinese uses 口 rather than 个. 我家有三个人 is understandable but less natural than 我家有三口人 when referring to the count of family members. 口 in this context emphasizes the family unit as mouths to feed.