得

得 is a single character with three readings that learners must keep separate. As a structural particle (de, neutral tone) it links a verb to a complement of degree or manner: 他跑得很快 ('he runs fast') — the 得 attaches the description 很快 to the verb 跑. As a modal verb (děi, third tone) it means 'must / have to' in spoken Chinese — 我得走了 ('I have to go now') — and is more casual than 必须 (bìxū). As a verb (dé, second tone) it means 'to obtain / to get' and shows up in compounds like 得到 (dé dào, 'to receive') and 得分 (dé fēn, 'to score points'). The same character; the reading depends on grammar and context. Beginners should master the de-particle pattern first since it's the most frequent.

Note: 得 is one character with three pronunciations and very different functions. Read 'de' it's a particle (toneless); read 'děi' it's a colloquial 'must'; read 'dé' it's a verb meaning 'to obtain.' Context — and tone — disambiguates.