20 countable nouns: a table, a pen, a pencil, a ruler, a notebook, a candy, a computer, a helicopter, an apple, a mirror, a comb, an eraser, a correction pen, a lamp, a pencil sharpener, a student, a bird, a phone, a church, a house
10 uncountable nouns: milk, water, hair, oil, butter, cheese, meat, bread, sugar, salt