## Word usage: 別 and 不要

別 and 不要 both mean "do not". They can be used in negative
/imperative/ sentences with or without a subject. They are placed
between the subject (if present) and the verb or adjective:

    (你) 別 (or 不要) 告訴他﹗
    別喝酒﹗ 別去那兒﹗
    不要吸煙﹗ 下午不要去﹗

Neither of these can be used to indicate negation in declarative
sentences. It is wrong to say 爸爸別請他走. One can say instead 爸爸不請
他走.