There are several kinds of citrus fruit . The most common are limes , oranges , grapefruit , tangerines and lemons . Out of all of them , it is the lemon that has found its way into a number of English language expressions . While eating an orange or grapefruit can be pleasant , we don't usually eat plain lemons . Lemons are really sour . The acid in them makes it really hard to eat them raw . Lemons are so acidic they can actually take the protective enamel off your teeth . So , biting into a lemon does not bring a smile to your face . In fact , when someone is unhappy she may have a puckered look on her face . In this case we can say she looks as if she just sucked on a lemon . We can also call this person a sourpuss . This is a person who always complains and always looks unhappy . With its really sour taste , sucking on a lemon is unpleasant . So , telling someone to "Go suck a lemon !" is a way of showing your anger . It's not really nice and sounds childish . But there are worse things you could say ! While we don't usually eat lemons raw , they can add taste and vitamin C to food and drinks . But in everyday speech , the word “lemon ” usually represents something poor , bad or broken . For example , if you hand someone a lemon , you have given them something that is broken or doesn't work . This expression means that you have cheated them . A "lemon " can also mean an unsatisfactory answer . As we said , a lemon can be something you bought that does not work . It is defective . Americans often use the word lemon to describe a newly-bought , but defective vehicle . Let's say you go to an automotive dealership and buy what you think is a good car . On the streets around the dealership , it runs perfectly . But on the drive home , everything goes wrong . The gas pedal sticks . Then it just stops running in the middle of the road ! You have bought a lemon . As you watch the tow truck take away the car for repairs , you call the dealership and demand your money back . The salesman says with a laugh , "No way ! All sales are final !" Now , many people would get angry . Not only do you not have a car , but you have lost a lot of money . But you don't get upset . You find a way to make this situation work for you . After all , you are a person who looks on the bright side . Your life's belief is : When life give you lemons , you make lemonade ! Here , the term "lemon " means a problem or difficulty in life . Lemonade is a cool refreshing drink . You could say it is the prize you get by overcoming difficulty with your good attitude . People who turn lemons into lemonade we call optimistic . This is a common phrase and we use in many different situations . Sometimes we don't even need to say the whole thing . If you simply say , "When life gives you lemons ..." people will know what you mean . So , back to our broken car story . You take the lemon of a car you bought at the dealership and you make lemonade . First , you learn about your rights as a buyer under a measure known as the lemon law . Under the lemon law , you will get your money back . But don't stop there . Why make a glass of lemonade when you can make a whole pitcher ! You warn friends and neighbors about that car dealership . You write an article for the local newspaper about lemon laws . The newspaper receives many emails and letters from people who had similar experiences . Knowing their rights , they also demand their money back for the lemons that were sold to them . The newspaper is so happy with the amount of responses that it offers you a part-time job writing stories about consumer issues . You've turned a bad experience into something good and you've helped others . Life gave you lemons and you made lemonade . Have you ever had to make lemonade from the lemons life gave you ? Or do you have a similar expression in your language ? But the fruit of the poor lemon is impossible to eat .