得 has three functions: to serve as a complementing particle, to mean have to or must, or to mean to obtain or to get.
complement is a structure following a verb/adjective that provides additional information of them.
得(de) is usually used to introduce complements that describe the result of their preceding verb.
The examples below show how 得 (de) as a complementing particle connects a verb with its result complement:
吃 (chī) refers to the process of eating, which does not include an end-point of this process; the complement 完 (wán) indicates the result ‘finishing up the food’ of the action 吃 (chī).
聽 (tīng) refers to the process of listening/hearing, which does not include the meaning 'successfully hearing something'; the complement 見 (jiàn) denotes the result ‘perceiving something’ from the action 聽 (tīng).
對 (duì) here is an adjectival complement used to describe that the result, which is the speech statement from the action 說 (shuō), is correct.
懂 (dǒng) here is a complement used to describe the result ‘understanding something’ from the action 看 (kàn).
Note that 得 can also be prononunced as děi. 得 (děi) is an auxiliary verb which means must or have to. In the following, 得 is an auxiliary verb:
When 得 is pronounced as dé, it means to obtain or to get.
Let's practice! Which 得 is which?