In English, we say "a chicken" to refer to a single chicken. The word "chicken" comes from Old English "cicen" or "cycen," which ultimately derives from the Latin word "gallus," meaning "rooster" or "cock." Here are some examples of "chicken" in sentences:

I bought a chicken from the farmer's market to make a roast for dinner.

The chicken is a type of bird that is often raised for its meat and eggs.

My little sister is afraid of chickens because they have sharp claws and beaks.

In Chinese, "一只鸡" can be translated as "yī zhī jī," which literally means "one chicken." Here are some examples of "一只鸡" in sentences:

我在农贸市场买了一只鸡来做烤鸡。(wǒ zài nóngmào shìchǎng mǎi le yī zhī jī lái zuò kǎojī.)

鸡是一种常被饲养来获取肉和蛋的家禽。(jī shì yī zhǒng cháng bèi sìyǎng lái huòqǔ ròu hé dàn de jiāqín.)

我的小妹妹害怕鸡，因为它们有锋利的爪子和喙。(wǒ de xiǎo mèimei hàipà jī, yīnwèi tāmen yǒu fēnglì de zhuǎzi hé huì.)