en connaître un rayon – French expression

en connaître un rayon — to really know your stuff — Mot du Jour

en connaître un rayon – it to know a spoke, a domain, to know it about a domain. In everyday French, en connaître un rayon is an idiomatic expression – that’s why you hear the EN in ‘en connaître’ and it means ‘to know a thing or two about something’, ‘to really know your stuff’.

« J’en connais un rayon sur la place des pronoms en français car j’ai fait la fiche de FrenchHour. »
- “I really know my stuff about the placement of pronouns in French because I studied the FrenchHour worksheet.”