Not to + infinitive is used to express prohibition or advise against an action. To + infinitive is used to express intention or permission to do something. Modal verbs like should, may, or can't are followed by an infinitive without the particle "to". Examples are provided to illustrate not taking "to" after a modal verb and using not to + infinitive to advise against actions for both second person singular and plural.

1. INFINITIVE (Neg.)
General Do
Not to + Infinitive Not to do
Examples:
- She told me not to tell anybody about our relationship.
- It’s bad for your health not to eat fruit and vegetables.

2. INFINITIVE (Neg.)
General Do
To + Infinitive To do
Remember! Remember!
Modals : should, may, can’t, …
- Modal verbs do not take the
- I should go to the swimming pool this
particle “to” and are followed by afternoon, but it may rain, I can’t drive
and I don’t want to get wet.
an infinitive without “to”
Examples:
-Don’t stand up and don’t talk to your mate. [For both 2nd person singular and plural]
-Let’s not go to the beach this weekend. [1st person plural]