Listen to the example below and you can hear how the triplet changes into a swing feel as the 2nd note fades away.
By taking out the 2nd note of every triplet (leaving you with the 1st and 3rd) you are producing the sound of a swing feel.
When counting a swing feel just say it like this (1 &2 &3 &4 &).
A Swing Feel On Paper
This is how triplets look musically. In the top music staff example there are three notes counted over two beats (1 & 2). In the bottom staff example there is four notes counted over two beats. The first three notes are triplets, so it will count like this (1 a & 2). To show a swing feel for a song you may see the following at the start of some music. As shown in the brackets 2 eighth note have the same value as 3 triplet notes.