know whereof one speaks

to know well the subject that one is speaking about. You are wrong! You do not know whereof you speak. He simply doesn't know whereof he speaks.

Name	Pronounced	Usage
Jaylon	JAY-lən	African American (Modern)
Beatrice	['bi:ətris]
Yonca	-	Turkish
SigrÍ&Eth;R	-	Ancient Scandinavian
Jarrod	JER-əd, JAR-əd	English
Hanga	HAWN-gaw	Hungarian