Bonjou, m' rele David. I do not understand how to determine when the definite determiner comes at the end of a sentence.

Bonjou David,

You mean the definite article?
Some people say there are three, some say there are four definite articles in Haitian Creole.
But I say ... you will see five!

 

You will see:

 

a - as in kiyè a (the spoon)
an – as in tan an (the time)
la – as in tab la (the table)
lan- as in lank lan (the ink)
nan – as in chanm nan (the room)  [people from some regions may say chanm lan instead of chanm nan]
and...
There are some exceptions, such as:
we say zanmi an instead of zanmi a, lanmou an instead of lanmou a, etc...

You'll find the answers in the following links:  The definite articles


Haitian Creole ↔ English Reference, Look up Haitian Creole and English Words