In Lithuanian language, one can say "You must not sleep" with one word - "tenemiega".
The following structure is:
Te- particle prefix, expressing command or a wish
-ne- negation prefix
-miega - 3rd person both Singular and Plural Present Tense.
Similar words are:
Tebūnie - "Let it go", "Let it be so". Tebūnie šviesa - "Let there be light".
Teneateina - "Don't come here"
Tenesilpsta rankos - "Don't give up" - literally "Let the hands not weaken".
Tenebijo - "Be not afraid".
Tenenustoja - "Don't stop".
Tenenusimena - "Forget it" - literally "Let you/them not remember"
Tenenyksta viltis - "Let hope not die"
Tenekalba - "Don't speak".
This form is rather archaic, used for blessings, rituals, curses, operas by Giuseppe Verdi, highlighting the feeling of unity, etc. Lithuanian cover "Let it go" from Frozen uses it, too. ^^
