Reduplication

Speakers of Mandarin Chinese often repeat words – a phenomenon known linguistically as reduplication. The most common reduplication is 謝謝/谢谢 (xièxie) – thanks.

Verbs, nouns, and adjectives can be reduplicated in Mandarin Chinese. The function of reduplication is to extend, intensify or soften the meaning of the words.
Reduplicated Verbs

Mandarin verbs are often reduplicated to soften their brusqueness or to lengthen the action. For example, 看一看 (kàn yi kàn) can mean, "have a look (take your time)". The meaning is similar to 看一下 (kàn yíxià).

Verb reduplication can also be done with completed actions:

    我看了一看。
    Wǒ kàn le yí kàn.
    I saw it (for a while).

The 了 le particle indicates that the action occurred in the past and is completed. In this type of sentence construction, the le particle comes after the first verb, and the 一 yī is optional:

    他等了(一)等。
    Tā děng le (yì) děng.
    He waited (a while).

Adjective Reduplication

Adjectives may be reduplicated to make them less direct: 小小的 (xiǎo xiǎo de) - a little bit small.

Adjective reduplication may also be done to intensify the adjective as in 漂漂亮亮(piāo piào liang liàng) – very beautiful. In this example, the adjective is a compound word of two characters 漂亮 (piào liang), so each character is reduplicated separately.
Compound Reduplication

The pattern in 漂漂亮亮 can be described as AABB, but that is not the only pattern used in compound word reduplication. Other patterns include AAB and ABAB.

Sometimes the pattern of reduplication can change the meaning: 高興高興 means “have some fun” and 高高興興 means “happy”.
Noun Reduplication

Nouns are sometimes reduplicated, but less often that verbs or adjectives. Examples of noun reduplication are 天天 (tiān tiān) – everyday, and 人人 (rénrén) – everyone.

Noun reduplication is more common in Taiwan and southern China than in Beijing Mandarin.