在大城市里，堵车是很常见的。

Zài dà chéngshì lǐ, dǔchē shì hěn chángjiàn de.

In big cities, traffic jams are very common.

这种花在公园里很常见。

Zhè zhǒng huā zài gōngyuán li hěn chángjiàn.

This kind of flower is very common in the park.

这是一个常见的汉字，你要多写几次。

Zhè shì yí gè chángjiàn de Hànzì, nǐ yào duō xiě jǐ cì.

This is a commonly seen Chinese character; you should write it several times.