R: "Bonjou, zanmi'm. Depi tanndat m pa wè w." (Hello, my friend. It's been a long time since I've seen you.) K: "Zanmi? Eske m konnen w?" (Friend? Do I know you?) R: "Ou te konn." (You did once.) K: "Oh...eskize mwen. Mwen pa sonje." (Oh...I'm sorry. I don't remember.)
So far so good :)
On the highlighted part, it's better to write "konnen" instead of "konn".
You may have the sentence as: "Ou te konnen m - You knew me"; or "Ou te konnen m yon lè - You knew me once."
and if you really don't want to have the whole sentence and you want a phrase similar to "You did once", then you could write: "Wi, yon lè" or "Wi, yon fwa", or simply "....yon lè".
Haitian Creole ↔ English Reference, Look up Haitian Creole and English Words