Things you can count, things you can't (A1 Grammar)
Some things you count one by one: one apple, two apples. Others we do not usually count on their own: water, rice, bread. A quick test: does one, two, three of it sound normal?
Can you count it?
one apple, two apples (you count them one by one)
water (we do not say "two waters" for the water itself)
one chair, two chairs (you count them one by one)
Try it: Which one do you count one by one (one, two, three)? (a book / rice / water) Answer: a book — If you picked rice or water, we do not count those on their own: "two rices" sounds wrong. Books you count one by one: one book, two books.
Uncountable: no a, no plural
When you can't count it, don't use a / an and don't add -s. Use some instead, or just the plain word.
I drink water every day.
Would you like some coffee?
She gave me some advice.
Not "I want a rice." — say "I want some rice.". You can't count rice, so no a here. Use some rice.
Try it: There is ___ on the table. (some bread / a bread / two breads) Answer: some bread — You can't count bread one by one, so no "a bread" and no "breads". Use some bread (or a piece of bread).
Common ones to get used to
A few everyday words don't get counted, even though it feels like they should. You will get used to these with practice: money, time, bread, rice, water, homework, advice.
I need some money. (not "a money")
She gave me good advice. (not "an advice")
I have homework tonight. (not "a homework")
Try it: Mei gave me ___ before the test. (some advice / an advice / some advices) Answer: some advice — "Advice" is one of the words we don't count: no "an advice" and no "advices". Use some advice. (These common ones come with practice.)
Counting them with a container
So how do you count water? Count what holds it: a glass of, a cup of, a piece of. Now the number goes on the container: two glasses of water.
a glass of water, two glasses of water
a cup of coffee
a piece of bread
Try it: Camila eats ___ with her soup. (a bread / a piece of bread / a piece bread) Answer: a piece of bread — You cannot count bread itself, so "a bread" is wrong, and "a piece bread" is missing of. Count a piece of it instead: a piece of bread.
Try it: Can you count it? Hiroshi needs ___ for the trip. (some money / a money / two moneys) Answer: some money — You can't count money one by one (no "a money", no "moneys"), so use some money. (When you can't count it, use some or a container.)