I’m glad you asked! I was thinking about this earlier, when writing about the Seven Deadly Sins made me think of envy, which is of course one of them.

These two are quite confusing, aren’t they? For both native and non-native speakers alike. Even if you know there’s a difference, and kind of know what that difference is, it’s hard to pin it down and put it into words, isn’t it? Let’s see if we can figure it out, shall we?

Let’s look at envy first, as it’s simpler. At its simplest, envy is wanting what someone else has. It might be something concrete, an actual object like their car or haircut.

Instinctively, jealousy feels very similar to envy. Oddly enough though, when you really look at it, it’s the opposite in some ways. While envy is about wanting something someone else has, jealousy is based on the fear of someone taking something from us. We might be jealous of a new colleague who might take our job from us, or at least take our position of favour with the boss.

Relationships can often be useful to demonstrate the difference between the two feelings. If there’s a girl you like who’s in a relationship with someone else, you feel envy because you want to be with her but can’t. However, if you’re in a relationship, but see your partner with a close friend of your gender, you might feel jealous, and fear that he might take her away from you.

So they are different, but still we confuse them. The main reason is that both share a feeling of inadequacy or lack. If we feel envy, it’s because we lack something that we want. When we feel jealousy, we imagine a situation in which we lack something which we currently possess. Both make us feel inadequate: one because of our perception of the present, and the other because of a future we imagine.

One thing you might feel sure about is the fact that jealousy is known as the green-eyed monster. Like so many words and phrases we take for granted, we have Shakespeare to thank for it. It first appears in Othello (1604):

Iago:
O, beware, my lord, of jealousy;
It is the green-eyed monster which doth mock
The meat it feeds on; that cuckold lives in bliss
Who, certain of his fate, loves not his wronger;
But, O, what damned minutes tells he o’er
Who dotes, yet doubts, suspects, yet strongly loves!

Shakespeare here might be comparing the mocking mercilessness of jealousy to a cat that toys with its prey, as many cats have green eyes. He may however originally have had a different reason for associating jealousy with green eyes. The Merchant of Venice (1596) featured the following passage:

Portia:
How all the other passions fleet to air,
As doubtful thoughts, and rash-embraced despair,
And shuddering fear, and green-eyed jealousy! O love,
Be moderate; allay thy ecstasy,
In measure rein thy joy; scant this excess.
I feel too much thy blessing: make it less,
For fear I surfeit.

Here, Shakespeare was probably invoking the association of the colour green with sickness.

As a green-eyed person myself, I’ve never been particularly offended by this expression, mainly because I’m more pre-occupied by the linguistic prejudice against left-handedness. Despite that though, I’ve never felt envious of right-handers. Or is that jealous…?