Hi, <br/><br/>When someone ask you about your nationality, do you have to put the indefinite particle "a/an" before the noun of nationality? Or is it an option? <br/><br/>e.g. <br/><br/>A: Are you an Irish? (Can you omit the "a") <br/>B: No, I am a scottish. (Can you omit the "a") <br/><br/>Could someone help me understand this please. <br/><br/>Thanks in advance.