quality

The word quality is a noun.

• It was Jan’s responsibility to check the quality of the final product.

In formal writing, quality should not be used as an adjective except when modified by such adjectives as high, low, poor, excellent and first. Hyphenate adjective-plus-noun compounds modifying another noun when ambiguity might otherwise result.

• Canadians produce high-quality products (or products of the highest quality, not quality products).
• First-quality furniture may be expensive, but it lasts for many years.

The noun quality is often used informally by itself as an adjective meaning high quality.

• Informal: Kelly wanted to spend more quality time with his children.
• Formal: Kelly wanted to spend more high-quality time with his children.