It is a two-line Poem, (which is probably for little children).
=     "When a verb is in the Negative Form, and uses the negative word  �NOT �,
          "We add the word  �DO �, to make the sentence complete."
    
 
An EXAMPLE
 
Positive Form: "I like bananas."
Negative         "I not like bananas."      This is not correct English.
Negative Form "I  do not like bananas".   This IS CORRECT ENGLISH.
 
I hope that this helps you. 
 
Les Douglas