Here are some examples of alliteration:
Phrases:
* Slippery snakes slithered slowly.
* Peter picked a peck of pickled peppers.
* White waves washed water wanderingly.
Sentences:
* The bright blue birds boasted beautiful bills.
* Cruel cruel crabs climbed cracking coasts.
* Friday feels fine for flying fishermen.
Literary examples:
* "She sells sea shells by the sea shore." (Traditional rhyme)
* "When the world was wild and woods were wide." (J.R.R. Tolkien, "The Lord of the Rings")
* "Good good good good good good good good good good good good good." (J.R.R. Tolkien, "The Hobbit")
Note: Alliteration doesn't always have to use the same exact letter, as long as the sound is the same. For example, "Peter picked a peck" uses the "p" sound even though the actual letters are different.