It's incorrect. The proper way would be: no digas mentiras. No dije mentiras.
Unless you're trying to say you didn't give lies, then it would be correct but one doesn't give lies, they tell them.
Di means I gave.
Answer : Incorrect.
Explanation : There is no verb tense in Spanish with the word "digues".
You could want to write the second singular person in the present in indicative mode of the verb "decir" = dices. "No dices mentiras" that means You do not tell lies.
You could want to write the second singular person in the present in subjunctive mode of the verb "decir" = digas. "No digas mentiras" that means I hope you do not tell lies.
You could want to write the second singular person in the present in imperative mode of the verb "decir" = digas. ¡No digas mentiras! that means I command you do not tell lies.
[tex]\textit{\textbf{Spymore}}[/tex]
