例子 (lìzi) means "example" or "instance" and is used when illustrating a point or giving a concrete case. Common phrases include 举个例子 (give an example) and 这是一个好例子 (this is a good example).
老师,你能举个例子吗?我没太听懂。
lǎoshī, nǐ néng jǔ gè lìzi ma? wǒ méi tài tīng dǒng.
Teacher, could you give an example? I didn't quite understand.
这是一个很好的例子,大家可以参考一下。
zhè shì yí gè hěn hǎo de lìzi, dàjiā kěyǐ cānkǎo yíxià.
This is a very good example; everyone can use it as a reference.
他用了好几个例子来说明这个问题。
tā yòng le hǎo jǐ gè lìzi lái shuōmíng zhège wèntí.
He used several examples to illustrate this issue.