Our character for today is 不
In simplified Chinese characters: 不
In traditional Chinese characters: 不
(It’s the same in both traditional and simplified Chinese characters)
This character is pronounced bù in the 4th tone.
However, in speech, when it comes before a 4th tone, then 不 is pronounced in the 2nd tone (even if it isn’t written out like that in the Pinyin pronunciation guide).
For example 不是 bù shì would actually be pronounced bú shì.
What it means:
不 means no or not. It’s not used so much on it’s own; it normally comes before a verb.
For example if somebody asks you 你喜不喜欢吃冰淇淋? (Do you like eating ice-cream?), you could answer no: 不喜欢 (literally: not like). It’s also commonly used with the character 是, which I introduced yesterday, to make 不是 (is not, it is not the case).