Texto sobre 的，地 e 得

O texto abaixo é do ótimo site chinesepod.com.

The Three Musketeers (的, 得, and 地)

In the first lesson of pretty much every introductory Chinese language text, students will learn 的. Generally (but not always -- we'll get to that in a bit) pronounced 'de' (with a neutral tone), it fills a variety of grammatical roles, including but not limited to indicating subordination (我的书 -- "my book") and nominalization (卖书的 -- "the person/thing that sells books"). 的 is pretty straightforward (especially if you have any background in languages like Japanese or Korean, where の and 의 play much the same role), and most people don't have much trouble mastering its most frequent usages.
Then, perhaps just a few weeks later, Chinese throws you a curveball. There are two other grammatical particles pronunced 'de' -- 得 and 地 -- but unlike 的 these two characters are frequently found in other contexts in which they play no grammatical role at all, have distinct meanings, and are not even pronounced 'de.' These two, and their relatively simpler, easier-to-master cousin 的, are the focus of this newsletter.

地 : not just the ground anymore

地 is a pretty common character, and is normally pronounced 'dì.' It means the ground, dirt, soil, the earth, etc. You might recognize it from such playful words as 地球 (dìqiú, the Earth) and 地方 (dìfāng, place). However, 地 also plays a grammatical role in which it connects an adverb to the verb that it modifies. Here are a couple of examples:

他认真地学习中文。 He studies Chinese seriously.
妈妈大声地唱歌。 Mother sings loudly.
老师慢慢地摇了头。 The teacher slowly shook his head.

In each of these three examples, 地 is pronunced 'de' and plays no role save for marking the adverb. Not all adverbs need 地 to mark them (several common monosyllabic adverbs like 多, 少, 早, 晚, etc. that are mostly used for imperatives, for instance), but most do. It should be noted that, as in the third example, monosyllabic adverbs are normally repeated before the 地 attaches them to the verb.

得 : you've gotta love it (seriously, you have to)

The third of the 'de' particles is 得, which has a day job being pronunced 'děi' and meaning 'must,' as in 我得走了 (I have to go). As a grammatical particle, however, 得 attaches verbal complements to verbs (when the verbal complement is negated, though, 不 replaces 得). Some examples include:

他说得很好。 He speaks well.
今天我困得厉害。 Today I'm very tired.
孩子最近表现得不好。 The child has acted poorly recently.

There are several different sentence structures in which 得 can be found, depending on whether or not the verb being modified takes an object. Yale University hosts a good rundown of the various combinations here.

的 : not always what it appears

Though I said earlier that 的 was the most straightforward of the three 'de' particles, it also leads something of a secret life. While its grammatical role is by far the most common, it also appears in a few other words sporting either the pronunciation 'dì' or (in only a single case, the word 的确) 'dí' (if that weren't enough, 的 is also pronounced 'dī' in a few colloquial words in which it refers a taxi -- imports from the Cantonese word for taxi, 的士). These aren't that confusing, really, but given the frequency at which 的 is used in its grammatical role, finding it in a different situation can be disorienting at first.
Gah! How am I ever going to get this straight?
It's not that bad, really. 的 is pretty simple, and 得 is used more frequently as a grammatical particle than it is as a standalone word. Only 地 is a bit tricky, but since it is normally bundled with another character as part of a word and found alone when acting as a grammatical particle, context should help you clear up any confusion.
And don't worry if you make a mistake or two with them, because native speakers do it all the time. In particular, using 的 for all three grammatical situations is extremely common in informal writing, the equivalent, perhaps, of writing 'u' instead of 'you.' People might have to reread your sentence to make sure they read it right, but in virtually every case you'll be understood (and probably gently chided, and then corrected).