A six letter word to command not to do something is to forbid.
The word that means "to say something that is untrue" is "lie".
something that cannot be avoided = inevitable
A four letter word meaning the foundation of something is base.
obsession
A six letter word to command not to do something is to forbid.
The word is "command".
The root mandat- in the word mandatory means "command" or "order." It signifies something that is required or obligatory.
Forbid you
The Spanish word "repitan" translates to "repeat" in English. It is a command form of the verb "repetir," which means to say or do something again.
A single word would be 'order'.
The meaning of the word forbid is to not allow something or prevent something from happening. It can also be applied to stopping someone from doing something - as in forbidding a princess from leave a tower.
Order
It is a command. It means "write".
One possibility is the word law.
vice maybe
The subject "you" is rarely stated in a command, so "Please stop talking" would be the usual form. This means "You should please stop talking." (Perhaps the question is "what word is not necessary in this command?")