What's the difference between "made from" and "made of"?
What's the difference between "made from" and "made of"?

There are some sentences.

1. Cheese is made from milk.
2. Books are made of paper.
3. Cars are made of metal, glass and plastic.
4. Cake is made from flour, sugar and eggs.

I still can't tell when I should use "made from" instead of "made of".

Question

What's the difference between "made from" and "made of"?
What's the difference between "made from" and "made of"?

There are some sentences.

1. Cheese is made from milk.
2. Books are made of paper.
3. Cars are made of metal, glass and plastic.
4. Cake is made from flour, sugar and eggs.

I still can't tell when I should use "made from" instead of "made of".

Answer

Great question!

Use "made from" when a substance (or substances) change significantly to become something else with different characteristics.

Cheese is made FROM milk.
Cakes are made FROM flour, sugar, and eggs.
Paper is made FROM trees.
Glass is made FROM sand.

Use "made of" when the characteristics of the ingredients and the characteristics of the noun are similar.

Books are made OF paper.
Trees are made OF wood.
Cars are made OF metal, glass, and plastic.
Forks and knives are made OF metal.

Answer

"Made from" indicates the ingredients use to make the item may have been transformed. You cannot identify the eggs and milk in your cake.
"Made of" indicates that you can identify those ingredients. You can pick out the metal, plastic, glass, etc. in your car.