Want to know a great way to phrase a warning? Try an If-Then Statement. An If-Then Statement clearly lets your kids know the exact consequence they’ll get if they misbehave. For instance, “If you throw that ball again, then I’m going to take it away from you.” This will cause them to connect their action with the consequence.
If your children break a rule you've been working on for some time, you may not want to give any warning. If, for instance, you have been training your child not to touch your laptop, and he does, say, "You know you may not touch my laptop. You need to sit in time-out."
Did you know that God used if-then statements all over the Old Testament? He was constantly telling Israel, if you do this, then this will happen to you.