There is a large range of abilities and understanding at two-years-old. A young two-year-old and an old two-year-old are at two totally different developmental levels. My daughter who just turned two throws things. I do two things for her. One is I say, "Don't throw that, or the toy is mine." If she throws again, the toy/food/etc. is taken away. She usually cries for a while but stops throwing. An older two-year-old I may place in time out at first offense. Keep in mind a young and old two-year-old has more to do with their developmental age, not their actual age. Different children develop at different rates. Knowing how well your child understands consequence depends on what you would use. Before they fully understand consequence. Still, vocalize your desire, so they are learning.