The jussive mood has many functions, including negation of the past tense and negation of commands.
The following are jussive particles:
لَمْ
لا
Examples:
لَمْ أذْهَبْ إلى الإجْتِماعِ
I did not go to the meeting.
لَمْ يُسافِروا إلى الشَرْقِ الأوْسَطِ
They did not travel to the Middle East.
See also: