Well i started learning english at 14 but I didnt move to the U.S. at 15 or 16. I'm not gonna lie it was tough since the syntaxes of english are so different.

Mainly you have to get used to (what I call)
English's backwards way of describing things and people. That was the biggest adjustment for me.
FOR EXAMPLE: When describing a sports car in french you say WHAT IT IS (a car) first and then describe it. In english it's backwards; You describe the thing before you ever say what
it is:
- Une voiture de sport americaine rouge et blanc
- A red and white american sports car
Notice in english you told me
it was red and white and american-made and of the sports kind before you ever tell me it's a fukking car. WHereas in french the very first thing you tell me is that it's a car, then you go on to describe it's origin, color , type, etc.
That was the biggest struggle for me.
And of course by nature, French speakers have trouble properly pronouncing the the word "THE" at the beginning. It's not a sound that we are used to. We try to pronounce it like "DE" or "DEUX" or better yet how we pronounce "oeufs" in french.
I managed to be as fluent in english as i am now because in the schools and workd environments I was in I didnt have too many fellow haitians or other creole or french speakers to speak to so it forced me to speak english constantly thus why im so fluent.