When you use "not" by itself in this context it makes the sentence appear strange and choppy. This would definitely not be okay for a formal exam. In this instance you want to use either "don't" or "do not". I hope this helps!! 😁

Agree with Jon. Once you have a phrase with the meaning of 'in order to', and you want to place a negative, the 'not'/negative has to come before the verb. It is fairly common, and not awkward at all!!

I know you've marked this as resolved, but (sorry) I disagree with both answers you've been given. Not only is this grammatical, it has a different meaning to the version with "do" inserted. Let me explain exactly what each sentence says. 1. Filmmakers make sick and twisted films to display violence and DO not concentrate on a substantial plot. This is saying that A. Filmmakers make sick and twisted films to display violence B. Filmmakers do not concentrate on a substantial plot 2. Filmmakers make sick and twisted films to display violence and not concentrate on a substantial plot. This is saying that A. Filmmakers make sick and twisted films in order to display violence B. Filmmakers make sick and twisted films in order not to concentrate on a substantial plot. With "do", it refers back to "filmmakers", meaning that the two parts of the sentence are entirely separate. Without "do", the "not" is referring back to "to": a second intention is being described. You could repeat "to" but it's not necessary, as in "Filmmakers make sick and twisted films to display violence and TO not concentrate on a substantial plot." Ugly but grammatical. So they are both grammatical and mean different things.

Thank you so much for such detailed explanations Mark! It really *does* help me a lot ;)

There are words we drop in English but "do" in not normally one of those words. If you are looking at a list of things like: "I do not like cheese, not like bacon, and not like pineapple" The way this should be written is "I do not like cheese, bacon, or pineapple". When you are listing words like this, the verb at the beginning of the list applies to all of the words and the not is implied. The word "that" can often be dropped. This is acceptable in most most situations. So rather than say "I bought the groceries so that I can make the dinner" you could say "I bought the groceries so I can make the dinner". For the sentence: Filmmakers make sick and twisted films to display violence and **not** concentrate on a substantial plot. This would be a very common way of writing on the internet but is not grammatically correct. It does not make your english sound more fluid. It does look more casual, but this sentence looking casual comes at the expense of possibile clarity and it is better to simply use the word "do". It does not really look like you know English better not to use do here, it only looks like you wrote the sentence in a hurry and without thinking about how it should be written. The sentence is completely understandable, but it is simply better to always include the word "do" in this situation. As to dropping a word like that, many people do not feel comfortable doing so because it is not really taught although it is grammatically acceptible in many situations. In most cases, it is better to use these words because of clarity. You will learn when you can drop a word like "that"from reading English once you know the rules. The American writer Thomas Pynchon drops the word "that"regularly, and it is grammatically acceptible to do so when he does it. His novels are very difficult, but if your English is at that level you can see someone who writes proper English manipulating the language for voice.