A sheep is a common farm animal that is valued for its hair and its meat. The plural form for this word does not have an "s": one sheep, two sheep, three sheep.
We saw some sheep while driving on the highway.
Farmers bring their sheep to the state fair to compete for prizes.
A sheep goes "baaaa."
The meat from a sheep is called mutton.
The hair of a sheep is called wool. Wool is popular material for winter clothing.
A group of sheep is a flock. A shepherd is a person who manages a flock of sheep.
A baby sheep is called a lamb.
Sheep are docile, easily-led animals. Sometimes people are compared to sheep in a negative way.
2015 is the Year of the Sheep on the Chinese calendar.
If you can’t get to sleep at night, try counting sheep.*
*Note: This is a commonly cited method for someone who can’t get to sleep. Sheep are imagined and counted, one by one. This is supposed to cause sleepiness. However, I believe there are better methods for falling asleep.