I am still confused about when to use an instead of a. Is it an hour or a hour and if someone is doing a master's degree in arts, is it an MA or a MA? With single letters and groups of letters pronounced as letters, be guided by the pronunciation. • a B road• a KLM flightBut an A road, an FA cup final, an SAS flight (R.W. Burchfield, The New Fowler's Modern English Usage)So it is an hour, an MA. Related Links:• How do I know when to put An Apostrophe in it's?• Is it an hour or a hour?• It is raining. Can this sentence stand alone as grammatically correct?• Is the word Data singular or plural?• Is the word Agenda singular or plural?• Is it acceptable to use THEY instead of HE or SHE? • Should I use A Singular or A Plural Verb with Collective Nouns?• Should I write : A Number of People is or A Number of People are?• What are the Plurals of octopus, hippopotamus and syllabus?• What is a Split Infinitive and why should I avoid using one?• The Word for The Whole that is Greater than the sum of the parts is ...• When should I use LESS and when should I use FEWER? • Which is correct : a European not an European? • Which is correct in this sentence : Lay or Lie? • Which is correct: My Friend and Me or my friend and I?• Which is the correct spelling : Oriented or Orientated?