Compound nouns are nouns made up of two or more words that function as a single unit to name a person, place, thing, or idea. They can be formed in three main ways:

1. Closed form – written as one word: *notebook, toothpaste, greenhouse*.
2. Hyphenated form – linked by a hyphen: *mother-in-law, check-in, runner-up*.
3. Open form – separate words used together: *swimming pool, high school, bus stop*.

In Written English
-Precision & brevity – Compound nouns condense meaning: *project deadline*, *fundraising event*.
-Formal & technical writing often uses them for clarity: *risk assessment report*, *market research study*.
-Consistency matters – follow the chosen form throughout the document.

In Spoken English
-Common in everyday speech: *car park*, *credit card*, *job interview*.
-Stress pattern – usually on the first word (*BLACKboard*, *POSTman*), though exceptions exist (*ice CREAM*).
-Avoid overloading speech with too many complex compounds — clarity is key.