地
dì
Turning adjectives into adverbs
地 is the -ly of Chinese: it turns a description of a thing into a description of an action.
Adj. + 地 + Verb
How it works
你要认真地学习 — you should study conscientiously. The 地 links the manner to the verb, and it always precedes the verb.
地 is pronounced de here, not dì. It's one of three de particles: 的 attaches to nouns, 得 follows verbs, 地 precedes verbs.
With two-syllable adverbs 地 is often dropped in speech: 认真学习.
Examples
nǐ yào rèn zhēn dì xué xí
你要认真地学习。
You should study conscientiously.
tā màn màn dì zǒu guò lái
他慢慢地走过来。
He walked over slowly.
qǐng ān jìng dì děng yí xià
请安静地等一下。
Please wait quietly.