Xiàng(向) and duì(對) both could serve as a preposition or a verb. When used as a proposition, xiàng(向) indicates that an action is performed towards a reference point, which can be a specific direction or a person. When duì(對) is used as a preposition, it means to or towards an object or target. When conveying the meaning of towards or to, the specific similarities and differences in usage between these two words are listed as following:
xiàng(向)/duì(對)+ person+ action verb
他向/對我揮手。
tā xiàng /duì wǒ huī shǒu.
He waved to me.
duì(對)+ something/person+ adjective / state verbs
老闆對你很失望。
lǎo bǎn duì nǐ hěn shī wàng.
The boss is very disappointed with you.
我對英語很感興趣。
wǒ duì yīng yǔ hěn gǎn xìng qù.
I am very interested in English.
xiàng(向)+direction/ noun(pronoun) represents an explicit direction of the activity + verb
你向東走一百米就到書店了。
nǐ xiàng dōng zǒu yī bǎi mǐ jiù dào shū diàn le.
You will arrive at the bookstore after walking a hundred meters eastward.
他向我們走來。
tā xiàng wǒ men zǒu lái.
He comes up to us.
Xiàng(向) also can mean “from” according to the context, but duì(對) doesn’t have this kind of usage.
他向我借了一百錢。
tā xiàng wǒ jiè le yī bǎi qián.
He borrowed a hundred money from me.
我們應該向他學習。
wǒ men yīng gāi xiàng tā xué xí.
We should learn from him.
