A, An or Some? Countable & Uncountable

Use a or an only with one countable noun. Use a before a consonant sound (a book, a university) and an before a vowel sound (an apple, an hour, an honest person).

Uncountable nouns have no plural and never take a/an. In positive sentences, offers and requests, use some with them:

• advice, information, news, furniture, luggage, work, homework, research, help, money, bread, milk, weather
• She gave me some advice (not an advice). We need some furniture (not furnitures). Would you like some cheese?

To talk about one thing, use a countable word instead (a tip, a sofa, a job) or a piece of + the uncountable noun: a piece of information. News ends in -s, but it is uncountable: some good news.