For example:
What a nice day!
A girl wants to say
She is like a flower market in May.
That always tests all her presentations.
God, say, maybe it rhymes with what's shown here.
Rhythm rhythm
(Note: capital letters are stressed syllables and lowercase letters are light syllables)
How nice/this is/a day (three steps)
A girl/think/say (three steps)
She's like FLO in May.
That al/waystries/ her whole/presentation (four steps)
The first two lines are the three steps of the light and heavy case, and the last two lines are the four steps of the light and heavy case, which constitute the rhythm of iambic. Like two beats in music. The beat of music is the rhythm of poetry.