It is a sub-variety of Antillean Creole, which is spoken in other islands of the Lesser Antilles and is very closely related to the varieties spoken in Martinique, Dominica, Guadeloupe, Grenada and Trinidad and Tobago. The intelligibility rate with speakers of other varieties of Antillean Creole is almost 100%. Its syntactic, grammatical and lexical features are virtually identical to that of Martinican Creole, though, like its Dominican counterpart, it includes more English loanwords than the Martinican variety.
Like the other Caribbean Creoles, Saint Lucian French Creole combines syntax of African and Carib origin with a primarily French-derived vocabulary. In addition, many expressions reflect the presence of an English Creole and Spanish influences are also present in the language.. The language is not considered to be mutually intelligible with standard French, but is intelligible with the other French creoles of the Lesser Antilles, and is related to Haitian Creole which has a number of distinctive features, but nonetheless are both mutually intelligible.
It is still widely spoken in Saint Lucia, though the actual number of speakers appear to have declined in the past decades. In the mid 19th century it was exported to Panama, where it is now moribund.
^Ethnologue code for Saint Lucian Creole French (spoken in Dominica and Saint Lucia) with the ISO 639-3 code: acf. However, it notes that their rate of comprehension is 90%, which would qualify them as dialects of a single language.