Japanese has many homophones. The meaning is usually understood in context, by kanji (if written), or by differences in pitch accent.
Today, let's take a look at this fun sentence:
きみ が わるい
kimi ga warui

Possible Meanings
Now, this could mean a few things:
君が悪い
You are bad.
気味が悪い
creepy (feeling); uneasy (feeling); bad (feeling); weird; hideous; etc.
(卵の)黄身が悪い
The egg yoke is bad.
Let's say someone stops you in a cafeteria and, looking at you, suddenly says, 「きみがわるい。」. Did that person just insult you? Does that person have the creeps? Or is it a public service announcement about the condition of the cafeteria eggs?
The Kanji
If this is written and you know the kanji, the intended meaning behind these three sentences will be obvious:
- 君 - you
- 気味 - feeling; sensation
- 黄身 - egg yolk
Pitch Accent
As stated above, sometimes homophones can be differentiated by paying attention to the pitch accent. This, of course, varies by dialect and can be very subtle, but here are the pitch accents in standard Japanese:
#1 and #3 (君 (you) and 黄身 (egg yolk)) have a 平板 heiban pitch accent. This means it starts down, goes up, and then stays up even with a following particle.
Listen to the sound file and compare with the next one until you hear the difference. It may help to use your finger as you pronounce it. Start with your finger down at き, then lift as you say み, and stay lifted.

#2 気味 (feeling) is 尾高 odaka which means it starts out exactly like the other two but goes down with a particle.
Start with your finger down at き, lift as you say み, and then back down with が.

Now for the Fun Part
We are back in the cafeteria. You notice your Japanese friend eating an egg. You go to him or her and say:
君の黄身は気味が悪い
Your egg yolk is disgusting.
If you can get the accent down (remember to go down with the が), no doubt, you will be complimented on your wonderfully weird Japanese.