Noun + noun (a tennis ball/a headache)

A noun + noun combination is when one noun modifies another noun. The first noun acts like an adjective that gives more information about the second noun. These combinations are common in everyday and business English.

• The first noun usually describes the type, purpose, material, or owner of the second noun.
• The first noun is usually singular (a tennis ball, not *tennis balls bag).
• Meaning is often specific and concise (sales report = report about sales).

Remember these points when you form noun + noun combinations:

• Use the first noun in singular form to modify the second noun: 'laptop bag', not 'laptops bag'.
• Make the second noun plural if needed: 'two tennis balls', 'three coffee cups'.
• Do not use an apostrophe for possession in these compounds: use 'company car', not 'company's car' (unless emphasizing ownership).

Think: first noun = type/description, second noun = the item itself

Watch out for these universal errors when using noun + noun combinations:

• Using a plural for the first noun (wrong: 'laptops bag' → correct: 'laptop bag').
• Adding an unnecessary apostrophe for possession (wrong: 'company's car' for a generic compound → use 'company car').
• Placing the plural marker on the first noun instead of the second ('two coffee cup' is wrong).
• Confusing noun + noun with adjective + noun patterns and changing word order incorrectly.

Always check which noun should carry the plural and avoid possessive forms unless you mean true ownership.