In English, nouns are identified or quantified by determiners. Articles, such as a, an, and the, are one type of determiner. Use the following guidelines to alleviate confusion regarding whether to use an article or which article to use.
I have a dog at home, also. (The word “dog” is a nonspecific noun since it doesn’t refer to any certain dog.)
(before a vowel): Carrie gave everyone an apple at lunch.
(before a consonant; with proper noun): He was wearing a Texas shirt.
I heard every noise all night long.
I tried each Jell-O flavor and liked them all.
(with count noun): I am going to eat that apple.
(with noncount noun): I am not too excited about this weather.
I didn’t have any donuts at the meeting because he ate them all.
Do you have enough donuts for everyone?
He ate some donuts at the meeting.
I’d like a little meatloaf, please.
There’s not much spaghetti left.
(with noncount noun): The weather is beautiful today.
(with singular count noun): Who opened the door?
(with plural count noun): All the houses had brick fronts.
I have a few books you might like to borrow.
Daryl and Louise have been traveling for several days.
Are those shoes yours?