When talking about physical size, we use big for most cases. Large is a little more
formal.
▶️ Everyday: Elephants are big animals.
▶️ In a textbook: Elephants are large mammals found in Africa and Asia.
In informal English, we use “large” for size when talking about clothes and drinks:
▶️ I ordered a big coffee with milk.
▶️ I ordered a large coffee with milk.
▶️ Sizes for shirts, socks, and other clothing items are small, medium, and large.
The word big is often used in collocations with a happening or event, for example:
▶️ a big accomplishment
▶️ a big decision
▶️ a big disappointment
▶️ a big failure
▶️ a big improvement
▶️ a big mistake
▶️ a big surprise
The word large is often used in collocations involving numbers and measurements.
▶️ a large amount
▶️ a large collection
▶️ a large number
▶️ a large population
▶️ a large proportion
▶️ a large quantity
▶️ a large scale