dishtinguish between substitutes goods and complementary goods.
dishtinguish between superior or normal goods,inferior goods.
The difference between substitute and complimentary is:A substitute is something used instead of a particular good or service, eg. for dinner , if you decide to eat beef instead of eating chicken because they both have protein, this is a substitute. If the price of chicken then increases, more people would be willing to buy beef since it is cheaper..Complimentary items are used in conjuction to each other, in other word, you need to buy both for something to typically work. eg. peanut butter and jelly are used in conjuction to each other and there fore are complimentary items. so if the price of peanut butter then increases, more people will decrease in buying both peanut butter and jelly because they are typically purchased together, the difference is that substitute is an item replacing a good or item when there is a price change and complimentary is two items that are bought together , both decreasing in demand because one item is being sold at a higher price and people need both two continue with their plans!Normal and inferior goods are classification given by economists to to goods judging on their behavior. Normal good is the most common type. It is said a good is normal when it's consumption increases when the income increases. Like clothes, when your income increases you buy more clothes. The opposite happens with inferior goods, of which consumption decreases when the available income increases. For example, used books and instant noodles: the more income you have the less used books and noodles you buy.A normal good is a good that a person will be more likely to buy the higher their income becomes. An inferior good is a good a person will be less likely to buy the higher their income becomes.