HOMONYMS

Started with watching Casablanca put me onto this
When the song said that a kiss is still a kiss 
I then wondered to myself is it great to be great
Maybe I would finish in a state living in a state

A thought then occurred to me is the light light ?
Have you got the gist of this poem all right alright 
One word two meanings is the my clue to you 
The sky outside is blue and I feel kinda blue too

I will go to the park now leaving my car in a car park 
Hoping this poem has left a mark with Mark 
Who is on the train with new people to train 
Working for a well known chain manufacturing a chain