There are so many phrases we use with our small beings of all sizes. To our 3 year old beings, we say "Play nice". To our 10 year old beings, we say, "Do good in school". To our 17 year old beings, we say "Be home at a reasonable hour". What doe these phrases really mean? What does playing nice look like? What is a good day at school? What is a reasonable hour? There are numerous ways that each sentence can be determined...which means the small being hearing this sentence can't' do what you are asking them. Even if they have the best of intentions, it is a direction they can not follow correctly.
In order for your small being to follow the directions given, you must BE CLEAR! Say what you mean and mean what you say. Give specific observable directions. If it is observable, then there is no need for interpretation (or more likely misinterpretation). There will be no confusion. If it is specific then your small being can actually apply your directions, to the best of their ability. Play nice, to me means share your toys, wait for your turn when playing a game and use kind words. Do good in school is dependent on how your child is currently doing in school. Today it might mean, raise your hand (no calling out in class), hand in your homework and walk silently through the halls with hands down (no running or talking in the halls). A reasonable hour for your teen being, may be 9 or 10 or 11 or 12, that depends on your household and the day of the week it is. Pick the hour you want your teen being home and say that.
Notice that my clear directions are stated with positive language. This is intentional. I want to remind how to behavior, and what is good. When we just give the negative direction, can be a confused feeling of "well, what can/should I do???".
Using clear language also allows for clear consequences. When you provide the clear direction, there is a way to see if it was accomplished. Did your teen being come home at 10pm as you stated was curfew for the night? It becomes yes or no. Then you know if reinforcement is appropriate (they can stay out just as late next time) or a negative consequence is appropriate (next time they ask to go out, curfew is 9:30). You do not need to interpret or guess at how much did your small being list to you...that becomes crystal clear when you provide clear directions.
Often times big beings don't provide clarity because they don't have it themselves. A very human experience...not knowing what the exact right answer is. Here is the secret to always having the right answer: Pick one! It really is that simple. Not easy but simple. Pick a clear answer for this moment. Later on or tomorrow you can pick a different clear answer. As big beings, we don't always have the right answer but we do have the ability to pick one clear answer and use it.
Simply, your small beings can't do what you are asking if you are not clear with them. Get clear!!