for instance: you feel sad because your father loves your brother better than you, it's JEALOUSY. you aggressively want to have / possess what your brother has, it's ENVY. most of the time, 'jealousy' shows more of feelings while 'envy' more of actions. :)

In modern English the two are often synonymous and used interchangeably as Jura stated. Properly speaking, there is a difference as romulus noted. -Jealousy is the negative emotion that arises from fear of losing something to someone else. So you could be relieved of your jealousy if your girlfriend stops flirting with your best friend, for example. -Envy is the negative emotion that comes from seeing that someone else has something that you don't have. In order to be relieved of your envy because someone has a Hummer and you don't, you have to get a Hummer for yourself, or arrange it so that the other person loses his Hummer. :) Envy (also called invidiousness) comes from the Latin word "in-vidia" which meant "to look evilly upon". Envy is one of the seven deadly sins both in Orthodox and Catholic tradition. In Russian 'envy' is translated as "зависть" which also has the root "видет" or "to see" and is related to the 'evil eye' or " о дурном глазе". Jealousy comes from the Latin "zelus" and referred to "a strong feeling (usually hostile) toward someone". One of these strong feelings was what later came to be known as 'jealousy'. In Russian 'jealousy' is closer to 'ревность'. But just as in English, it can also be considered a synonym for "зависть" or envy. So you could be both jealous and envious of someone at the same time: You could be jealous of the captain of the football team because your girlfriend loves him and at the same time be envious of him because he is so rich. It seems that the two words have been related for a long time so it is not surprising that they are often used as synonyms. no room for examples ....sorry!

You can use both as people will understand that there is a very fine line in their meaning.

Envy is the desire for something that someone else has, or a feeling of ill will over another person's advantages in general: My envy of your success has made me bitter. Jealousy is a resentful suspicion that someone else has what rightfully belongs to the jealous person: Out of jealousy, he followed his wife. The favored treatment of the daughter created jealousy in the son.