Meaning of bù dé:
bù dé
不得
Adverb
must not; may not; not to be allowed
Nǐ zài túshūguǎn nèi bùdé dàshēng shuōhuà.
你在图书馆内不得大声说话。
You must not speak loudly in the library.
Zài túshūguǎn nèi, bùdé dàshēng xuānhuá.
在图书馆内，不得大声喧哗。
In the library, one may not speak loudly.
Zài túshūguǎn lǐ bùdé dàshēng shuōhuà.
在图书馆里不得大声说话。
In the library, it is not allowed to speak loudly.
Verb
cannot
Kǎoshì qíjiān wǒmen bù dé shǐyòng shǒujī.
考试期间我们不得使用手机。
We cannot use mobile phones during the exam.
