Hi Irina, The first sentence is grammatically correct. The difference between these two sentences is that "not to" is used when we are describing something that was spoken earlier, whereas "don't" is used when we are giving a direct spoken instruction to someone. Example: I told John not to touch my belongings. (You are telling someone what you told John earlier) I told you not to touch my belongings. (You are reminding John what you told him earlier) "Don't touch my belongings." (You are giving a reminder there and then) When we transform a direct speech (involving a command) to reported speech, we commonly change "do not" to "not to". Example: Dad said, "[Do not] move the cabinet." Dad told me [not to] move the cabinet. I hope this helps.

I advise you not to miss your English classes, because you would miss out on meeting interesting native English speaking people. Как я. You can also say, "I advise you: don't miss your English classes". The first one is one complete sentence; with two clauses. The second sentence is correct IF you put in a comma (,) or semi-colon ? (this ":" or this ";:) because it is like a) I am advising you, and b) this is the advice or command - Don't miss the class.

Lance has a good answer, but you can add “that” to the second sentence and have it be perfectly correct: I advise that you don’t miss your English classes. A small point: at least in the US, you will hear the word “recommend” much more often than “advise” in this type of sentence.