There are normally two words that you use for ‘know’ in Chinese, depending on the situation:
知道 zhīdào and 认识 rènshi
认识 rènshi normally means to know of a person or a place, or (be able to) recognise
你认识路吗？nǐ rènshi lù ma? Do you know the way?
你认识多少字？Nǐ rènshi duōshao zì? How many characters do you know/recognise?
你们在哪里认识的？Nǐmen zài nǎlǐ rènshi de? How do you know each other?
知道 zhīdào normally means ‘know of’, ‘know about’ or ‘know a fact
我不认识他，但是我知道他
wǒ bù rènshi tā, dànshì wǒ zhīdào tā
I don’t know him, but I know of him.
你知道飞机场怎么走吗？
Nǐ zhīdào fēijīchǎng zěnme zǒu ma?
Do you know how to get to the airport?
我知道一些关于孔子的事
Wǒ zhīdào yīxiē guānyú kǒngzǐ de shì
I know some things about Confucius?