Create a formula that returns a month.

Create a formula that returns a month.

I am trying to create a formula in my opportunities module which returns the month when a date is inserted into the 'Closing Date' field. E.g. 12/05/2016 is inserted into Closing Date, formula returns 'May'.

Someone spoke to me on the phone about this and he said he would send me the syntax to use, but I never received it. It would help if someone could send me the syntax to use.