نباید

What it means

نباید (nabâyad) is the negative modal meaning “must not” or “should not.” It is formed by adding the negation prefix ن- (na-) to باید (bâyad), the Persian modal that expresses necessity or obligation (“must,” “should,” “have to”). Like باید, نباید is invariable: it does not conjugate for person or number, and the verb that follows it takes the subjunctive stem. So where باید بری means “you must go,” نباید بری means “you must not go.” The strength of prohibition ranges from mild advice to firm command depending on context and tone. In formal writing you may see نمی‌بایست or نمی‌باید for the past prohibition, but نباید covers both present and future prohibition in everyday speech.

How to use it

• نباید دیر بیای (nabâyad dir biâyi) “You must not come late.”
• نباید اینو به کسی بگی (nabâyad ino be kasi begi) “You must not tell anyone this.”
• بچه‌ها نباید تنها بمونن (bachehâ nabâyad tanhâ bemunan) “Children must not be left alone.”
• نباید اینقدر نگران باشی (nabâyad inghad negarân bâshi) “You should not be this worried.”

Cultural note

Iranian parents and teachers use نباید frequently as the primary tool for setting limits on children’s behavior. The directness of نباید, without softening hedges, signals a firm boundary. In polite adult-to-adult speech, Iranians often prefer نباید framed with a reason («چون…، نباید…») or moderated with نمی‌خواد (it is not necessary) to avoid sounding harsh. When نباید is said with emphasis in casual speech, it can carry a tone of warning or even mild reproach.

References

• Dehkhoda
• Vajehyab