Tom couldn't hear the cockerel crowing.

Beware of the cockerel. It bites.

Did you hear the cockerel crowing?

The cockerel's splendid red cockscomb is thought to play a part in determining gender and breed.

The cockerel crows early in the morning.

Did you hear a cockerel crowing as well?

The cockerel, herald of the morning, wakes those of us sleeping.