The part of a sentence that provides information about the subject is called the predicate. In Japanese, this is known as 述語(じゅつご), or 'statement word'. な-Adjectives can act as the predicate on their own, or they can be placed at the very end of a sentence to describe the subject.

Keep in mind that every な-Adjective also has the properties of a noun. Because of this, when used as a predicate, they often feel more like a noun than a descriptive word.

• 静か(しずか)。
  It's quiet.
• 公園(こうえん)は安全(あんぜん)です。
  The park is safe.

When a な-adjective is used alone without a subject, it conveys a meaning similar to English phrases like 'It's beautiful' or 'It's clean'. The listener must infer what 'it' refers to based on the situation.

Caution

In contrast to い-Adjectives, the form of a な-Adjective changes based on its position in a sentence. When it concludes a sentence, it must be paired with だ or です (though だ is often dropped in informal speech). When it comes before a noun to modify it, it must be followed by な, which is how this adjective type gets its name.

For many sentences, the subject being described by the predicate can be marked with either は or が. The most natural choice is determined by context. As a general rule, が is preferred when you want to single out something and contrast it with other similar items.

• 便利(べんり)な店(みせ)は高(たか)いです。
  Convenient stores are expensive. (In general)
• この便利(べんり)な店(みせ)が高(たか)いです。
  This convenient store is expensive. (Compared to other convenient stores)

In this case, が is used to highlight that this particular store is expensive in a way that sets it apart from others. Using は in a sentence like this would sound awkward.

Fun Fact

The majority of な-Adjectives are derived from words that originated in other languages, such as Chinese or English.