An attributive noun is a noun used before another noun to describe or classify it, functioning like an adjective. It tells us what kind, purpose, or category the main noun belongs to. For example, "school bus" means “a bus for school,” and "coffee mug" means “a mug for coffee.”

Structure:

[Attributive Noun] + [Main Noun]

In written English, attributive nouns make sentences concise: "CSR proposal" (instead of “a proposal for CSR”) or "livelihood project report" (instead of “a report on a livelihood project”). They are common in headlines, reports, and technical writing.
In spoken English, they are also frequent, with stress usually on the main noun: "training workshop", "fundraising campaign". Avoid stacking too many together in speech for clarity.
They differ from possessives and adjectives, and usually remain singular unless part of a fixed phrase, e.g., "shoe store", "sports shoes shop".