Poets have many tools that they can use to create their poems. The one you might be most familiar with is the effect of sound. When words are spoken aloud, they have lots of great sound qualities that poets can incorporate into their poems.
The most recognizable sound effect used in poems is rhyme. When two words rhyme, they have a similar ending sound. Words that end in the same letters, such as "take" and "make" rhyme, or words with different endings but the same sound rhyme, such as "cane" and "pain." Poetry also makes use of near rhymes (or slant rhymes), which are words that almost rhyme, but not quite -- such as "bear" and "far."
Other sound effects make use of repeating letters or combinations of letters. Consonance is repeating the same consonants in words that are near each other. The statement "mummy's mommy was no common dummy" is an example of consonance because the letter m is repeated. If the repeated letters appear only at the beginning of the words, this is known as alliteration. For example, "the big brown bear bit into a blueberry" is an example of alliteration because several words close together begin with the letter b.
If the letters or sounds that are repeated are vowels instead of consonants -- as in "I might like to fight nine pirates at a time" -- it is known as assonance. Assonance can be pretty subtle sometimes, and more difficult to identify than consonance or alliteration.
Sometimes a poet might want to make you imagine you're hearing something. This is part of a concept called auditory imagery, or giving an impression of how something sounds. One common way to create auditory imagery is through the use of onomatopoeia. Think about words that describe a sound -- words like buzz, clap or meow. When you say them aloud, they kind of sound like what they are describing. For example, the "zz" in the word buzz kind of sounds like the noise a bee makes.
There are many other types of sound effects that a poet can use, but these are just a few of the most common ones. Now that you understand how poets choose which words to use, let's look at how poets put these words together by choosing to (or not to) follow a structure.