  Inspired by embedded programming languages, an embedded CNL (controlled
natural language) is a proper fragment of an entire natural language (its host
language), but it has a parser that recognizes the entire host language. This
makes it possible to process out-of-CNL input and give useful feedback to
users, instead of just reporting syntax errors. This extended abstract explains
the main concepts of embedded CNL implementation in GF (Grammatical Framework),
with examples from machine translation and some other ongoing work.

Computation and Language