Hi, I'm dorky, how are you?
I speak three dialects of French (Quebec, France & Haitian Creole)
Haitian Creole wouldn't ordinarily be categorized as a dialect of French, but as a, well, creole, a nascent/new language whose life span can be measured in decades, rather than centuries. Haitian Creole is a sapling to the ancient redwood that is French.
The boundary between "a dialect" and a distinct language can be blurry and influenced more by politics than common ground and degrees of intelligibility. For instance, Catalan was regarded for years as a dialect of Spanish or French (or more intolerantly, as "Bad Spanish/French"), but is currently recognized as a distinct language. And while Catalan is spoken in Valencia, it is referred to vociferously as VALENCIAN. A more volatile example would be that of the Baltic states (Croatian/Serbian/Bosnian/Montenegrin/etc.)
Creoles arise in a time and place where people from different backgrounds without a common language are forced to live and communicate with each other for whatever length of time. What forms first is a pidgin- simple phrases from the languages spoken by the population to fill the need for basic communication (We have water? Where is the bathroom? Let's fuck!). Pidgins only last as long as the contact situation. Should the population become relatively stable, with children being born and raised in this environment where a pidgin has become a common parlance, the conditions for a creole arise. The children take that existing pidgin as the basis for their mother tongue, but transform it and fill in whatever grammatical gaps the pidgin hadn't filled or addressed (such as tenses, prepositions, word order, stress patterns).
Studies of creoles show a great deal of common ground in terms of grammar, despite the source languages having no relationship to each other and minimal commonality, suggesting the existence of a Universal Grammar, an idea mostly attributed to Noam Chomsky. Think of it as humans are born with some degree of "factory programming" with regards on language and how to use it.
Off topic, but I'm a language dork and couldn't resist!
And to answer the actual question posed, I am an anglophone reasonably competent in Spanish, and I very briefly studied Catalan.