Characters
Your sentence
你 有 几个 孩子?
Words in this sentence
你
you (informal, as opposed to courteous 您 (nín)); you (Note: In Taiwan, 妳 is used to address females, but in mainland China, it is not commonly used. Instead, 你 is used to address both males and females.)
有
to have; there is; (bound form) having; with; -ful; -ed; -al (as in 有意 (yǒuyì) intentional)
几个
a few; several; how many
孩子
child