SQL Server how to change 1 letter from lower case into upper case

Hi All, i want to convert my table value from upper case to lowercase in sql server. i have tried my code below but am not get any output, i want to convert first letter of the word into lowercase eg: Test=test select CONVERT(VARCHAR,YEAR(GETDATE()))+'_'+DATENAME(MM,GETDATE()) OUTPUT: 2016_May EXPECTED OUTPUT: 2016_may thanks in advance.