know (one's) beans

To be knowledgable about and/or very familiar with something. I had no idea you were such a good piano player—you really know your beans!

Name	Pronounced	Usage
Posy	PO-zee	English
Remiel	-	Judeo-Christian Legend
Rosemonde	-	French
Finnuala	-	Irish, Irish Mythology
Tiziana	tee-TSYAH-nah	Italian
Aylin	['eilin]