Write a SQL Query to find first day of month?

SELECT DATENAME(dw, DATEADD(dd, - DATEPART(dd, GETDATE()) + 1, GETDATE())) AS FirstDay
DatepartAbbreviations
yearyy, yyyy
quarterqq, q
monthmm, m
dayofyeardy, y
daydd, d
weekwk, ww
weekdaydw
hourhh
minutemi, n
secondss, s
millisecondms