得 děi

得 have three pronunciations, corresponding to three different meanings:

1, 得 HSK4 ([děi] Auxiliary Verbs, 助动词) is usually used in oral, means [need; must; should], some usages below;

2, 得 HSK2 ([de] Auxiliary) used to link a verb or an adjective to a complement which describes the manner or degree;

  eg) 她高兴得笑了。(She laugh with pleasure. )

3, 得 HSK2 ([dé] Auxiliary), "Verb. + 得 + Modal Complement" is used to illustrate the action or the subject;

  eg) 她唱歌唱得很好。(She sings well.)