此

cǐ rén shì gè lǎo shī

此人是个老师。

This person is a teacher.

cǐ chù jìn zhǐ xī yān

此处禁止吸烟。

Smoking is not permitted here.

cǐ wù yǒu dú

此物有毒。

This thing is poisonous.

cóng cǐ wǒ bù zài shì nǐ lǎo shī

从此，我不再是你老师。

I'm not your teacher any more from now on.

cóng cǐ yǐ hòu tā jiù bù shì xué sheng le

从此以后，他就不是学生了。

From then on, he was not a student.

yóu cǐ wǎng nán jiù shì yī yuàn

由此往南，就是医院。

There will be a hospital if you go south from here.

cháng cǐ zhè yàng

长此这样

go on like this