I think you are asking about when to use "don't" and when to use "not to" (not "no to"). I think of it this way. * don't - negates the main verb in a sentence or a clause. * not to - negates a verb in an adverbial or noun phrase, usually expressing a purpose. Examples: - I don't know why he doesn't take my advice. ("don't" negates the main verb, "doesn't" the verb in the sub-clause) - I told him not to ignore my advice. ("not to ..." is an adverbial phrase complementing the main verb "told") - Make sure (that) you don't act too rashly. ("don't" negates the main verb in that-clause) - Be sure not to act too rashly. ("not to" is an adverbial phrase complementing "make") So "don't" works on (i.e. negates) the verb of the main predicate (the description part of the sentence) while "(not) to" describes the purpose, intention, meaning, etc. of another verb. The former is thus at the main level, and the latter has a subordinate role.

Hi, Youali! We don't use "no to" in English unless the "no" is part of another action (for example: "Say 'no' to drugs because drugs are very harmful"). "Don't" has two primary uses that I can think of at this moment: As a command: "Don't cross the street when the traffic light is red." "Don't smoke around children." "Don't talk when the teacher is talking." As a present tense (simple or continuous) negative for the first-person singular and plural (I/me, we/us), second person (you), and third-person plural (they/them): "We don't eat dinner at seven." "You don't know how to swim." "They don't believe his story." If there is another common usage for "don't," I cannot think of it at this time. Perhaps another English speaker can add to my answer. I hope this helps you =)