Mandarin prepositions are used to link nouns, pronouns, and noun phrases within a sentence. Mandarin prepositions can refer to movement within time or space, or function as general prepositions such as the English prepositions with, to, or for.

GENERAL PREPOSITIONS
The most common general Mandarin prepositions are:

對 / 对 – duì – to (someone)
跟 – gēn – with; from
給 / 给 – gěi – to; for
替 – tì – for (someone)

用 – yòng – with
USING MANDARIN PREPOSITIONS
The object of a Mandarin preposition comes directly after the preposition, and the OBJECT + PREPOSITION phrase (the Prepositional Phrase or PP) comes before the verb, as in this example:

Zhègè xiǎo nǚhái duì wǒ wēixiào.
這個小女孩對我微笑。
这个小女孩对我微笑。
This little girl smiled at me. (literally: This little girl at me smiled.)
Modifiers such as adverbs are placed either before the PP or after the verb’s object:

Wǒ míngtiān huì gēn tā shuō.
我明天會跟他說。
我明天会跟他说。
I will speak with him tomorrow. (literally: I tomorrow will with him speak.)
MANDARIN PREPOSITION EXAMPLES
Here are a few sentences with Mandarin prepositions. Please note that there may be more than one translation of English prepositions. Mandarin prepositions have stricter usage than English.

GĒN
Jīntiān wǎnshang wǒ yào gēn tā qù chīfàn.
今天晚上我要跟他去吃飯。
今天晚上我要跟他去吃饭。
This evening I am going to have dinner with him. (literally: Today’s evening I am going with him to go and eat food.)
GĚI
Lǐ xiānsheng xiǎng gěi tā de tàitai mǎi yī tiáo jīn xiàngliàn.
李先生想給他的太太買一條金項鍊。
李先生想给他的太太买一条金项炼。
Mr. Li is thinking of buying a gold necklace for his wife. (literally: Mr. Li is thinking for his wife to buy a gold necklace.)

Tā yǐjīng tì wǒ xiū hǎo le.
她已經替我修好了。
她已经替我修好了。
She has already fixed it for me. (literally: She already for me fixed it.)

YÒNG
Tā yòng mù gùn qiāo wǒ de tóu.
他用木棍敲我的頭。
他用木棍敲我的头。
He hit me on the head with a stick. (literally: He with a stick hit my head.)