Hi,<br/><br/>Can we use the name of a dog, car, or airplane countably in that we can attach an indefinite article 'a' or 'an' in front of it?<br/><br/>a Chihuahua -- When should we use without 'a' or 'an'?<br/><br/>a Cadillac -- When should we use without 'a' or 'an'?