This document discusses fixed expressions in English. It notes there is no agreed upon terminology and definitions can vary. Idioms are defined as multi-word phrases whose meanings are not fully predictable from the individual words. Idioms typically have both a literal compositional meaning and a non-compositional idiomatic meaning. Fixed expressions include idioms and other phrases like proverbs and collocations that vary in their degree of compositionality. Institutionalization, fixedness, and non-compositionality are identified as the main factors in defining fixed expressions, though there is variability. Other criteria mentioned include orthography, syntactic integrity, and phonological properties. Examples of common English idioms and fixed expressions are provided.