What is the effect of using an imperative verb?
Imperative verbs are used when you want to ask someone to do something for example:
Open the window, please. - In this sentence open is a verb used in imperative mood.
If you use negation together with an imperative verb you will get a ban. For example:
Do not park your car here. - this sentence tells that it is forbidden to park in the area. Verb to park is used in imperative mood with negation "do not park".