"Peyi mwen an nan detrès" - Why is "an" and nan" needed? And why do some possessive phrases have a definite article at the end? (eg: Did you see my bag? -Eske ou te wè valiz mwen an?)

The definite article together with “mwen” make up the possessive adjective.

1.

peyi mwen an

Or

peyi m nan
my country

2.

peyi ou a

Or
peyi w la
your country

3.

peyi li a

Or
peyi  l la
his/her country
 

4.
peyi nou an
Or
peyi n nan
our country


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