Mandarin words are often doubled, as in 謝謝 /谢谢 xièxie (thanks). There are several reason for this. Sometimes the words are doubled because they sound better this way. Xiè sounds a bit awkward on its own, and by doubling it, we also increase our gratitude. Here are some other uses of doubled words.
Repeated Adverbs

Adverbs are often repeated in the pattern:

    ADVERB ADVERB 地 (de)

In this pattern the adverb precedes the verb, as in this example:

     Tāmen màn màn de zǒu guòlái.
    他們慢慢地走過來。
    他们慢慢地走过来。
    They walked over slowly.

Negative Form

To create the negative form of this pattern, 沒有 (méiyǒu) is place before the adverb:

    Tā méiyǒu guāi guāi de zuò zháo.
    他沒有乖乖地坐著。
    他没有乖乖地坐着。
    He (the child) didn’t sit properly.

Examples of Repeated Adverbs

Here are a few more examples of the repeated adverb pattern:

    Tā tōutōu de bǎ lǐwù cáng qǐlai.
    他偷偷地把禮物藏起來。
    他偷偷地把礼物藏起来。
    He secretly hid the present.

    Tā méiyǒu qīngqīng de bǎ mén guān shàng.
    她沒有輕輕地把門關上。
    她没有轻轻地把门关上。
    She didn’t close the door quietly.