I have two children 我有兩个孩子 [Pinyin] wō yǒu liǎng gē hái zi I have two sons 我有兩个兒子 [Pinyin] wō yǒu liǎng gē ér zi I have three cars 我有三辆車 [Pinyin] wō yǒu sān liàng chē I have three houses 我有三栋房子 [Pinyin] wō yǒu sān dòng fáng zi

for sons, use 个 for vehicles use 辆/架 for house, 栋/间, 座 for mansions and large buildings.

我有兩個小孩 我有兩個兒子 我有三輛車 我有三棟房子

Hi, I'm a Chinese native speaker in Taiwan. I can answer the most common counting objects we usually use to your questions. I have two children 我有"兩個"孩子 I have two sons 我有"兩個"兒子 I have three cars 我有"三台"車 or 我有"三輛"車 I have three houses 我有"三棟" 房子 Hope these help~ :)

我有两个孩子 我有连个儿子 我有两辆汽车 我有三座房子