In Japanese grammar, a predicate is the part of a sentence that provides information about the subject, typically describing an action, state, or quality, and completes the main clause. It is the core element that forms the conclusion of a sentence.
Understanding Predicates in Japanese
A predicate serves as the central descriptive element of a sentence, determining its fundamental meaning and often appearing at the very end. Unlike English, where predicates are primarily verbs and their objects, Japanese predicates can take various forms, fundamentally shaping the sentence's structure and nuance.
Types of Predicates in Japanese
Japanese grammar identifies three primary types of words that can function as predicates: verbs, adjectives, and nouns (when used with a copula). Each type plays a distinct role and undergoes specific inflections.
Verbs (動詞 - Dōshi)
Verbs are perhaps the most common type of predicate, expressing actions, occurrences, or states of being. They are highly inflected to convey different tenses, polarities (affirmative/negative), and politeness levels.
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Examples:
- 食べる (taberu) - to eat
- 行く (iku) - to go
- ある (aru) - to exist (for inanimate objects)
- いる (iru) - to exist (for animate objects)
Sentence Example: 私は食べる。 (Watashi wa taberu.) - I eat.
Adjectives (形容詞 - Keiyōshi)
Adjectives function as predicates to describe qualities or characteristics. In Japanese, adjectives are divided into two distinct categories based on their ending and inflection patterns: i-adjectives and na-adjectives.
i-Adjectives (イ形容詞)
i-adjectives always end in the hiragana character い (i) in their dictionary form (e.g., 楽しい tanoshii - fun, 寒い samui - cold). They directly inflect to indicate tense and negation without requiring a separate copula.
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Characteristics:
- End in い (i) in their plain, non-past, affirmative form.
- Inflect directly.
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Examples:
- 高い (takai) - high, expensive
- 美味しい (oishii) - delicious
- 寒い (samui) - cold
Sentence Example: この本は高い。 (Kono hon wa takai.) - This book is expensive.
na-Adjectives (ナ形容詞)
na-adjectives (also sometimes called adjectival nouns) typically do not end in い (i) in their dictionary form (e.g., きれい kirei - beautiful, 静か shizuka - quiet). When used as predicates, they require the copula だ (da) (plain form) or です (desu) (polite form) to complete the sentence. They are called na-adjectives because they often use な (na) when directly modifying a noun (e.g., きれいな花 - kirei na hana - beautiful flower).
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Characteristics:
- Do not typically end in い (i) in their plain form.
- Require a copula (だ/です) when functioning as a predicate.
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Examples:
- きれい (kirei) - beautiful, clean
- 静か (shizuka) - quiet
- 有名 (yūmei) - famous
Sentence Example: 彼女はきれいです。 (Kanojo wa kirei desu.) - She is beautiful.
Nouns (名詞 - Meishi)
Nouns can also function as predicates, typically to state what something or someone is. When a noun acts as a predicate, it must be followed by a copula, most commonly だ (da) in plain form or です (desu) in polite form.
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Examples:
- 学生 (gakusei) - student
- 医者 (isha) - doctor
- 日本人 (nihonjin) - Japanese person
Sentence Example: 彼は学生だ。 (Kare wa gakusei da.) - He is a student.
Predicate Inflection: Tense and Polarity
A defining characteristic of Japanese predicates is their inflection. Predicates change their form to indicate two crucial grammatical aspects: whether they are affirmative or negative and whether they refer to non-past (present/future) or past events. This system allows for precise temporal and polarity distinctions within a sentence.
The following table illustrates common plain form inflections for various predicate types:
| Type | Affirmative Non-Past | Affirmative Past | Negative Non-Past | Negative Past |
|---|---|---|---|---|
| Verb (taberu - to eat) | 食べる (taberu) | 食べた (tabeta) | 食べない (tabenai) | 食べなかった (tabenakatta) |
| i-Adjective (takai - expensive) | 高い (takai) | 高かった (takakatta) | 高くない (takakunai) | 高くなかった (takakunakatta) |
| na-Adjective (kirei - beautiful) | きれいだ (kirei da) | きれいだった (kirei datta) | きれいではない (kirei dewa nai) | きれいではなかった (kirei dewa nakatta) |
| Noun (gakusei - student) | 学生だ (gakusei da) | 学生だった (gakusei datta) | 学生ではない (gakusei dewa nai) | 学生ではなかった (gakusei dewa nakatta) |
(Note: These are plain forms. Japanese also has polite forms, which follow different inflection patterns.)
Why Predicates are Important
Understanding predicates is fundamental to mastering Japanese grammar. They dictate the sentence's core meaning and how it relates to time and negation. By learning their different types and inflection patterns, learners can construct grammatically correct and meaningful Japanese sentences. For further exploration of Japanese grammar concepts, resources like Tae Kim's Guide to Learning Japanese Grammar or JLPT Sensei offer comprehensive insights into sentence structure and verb conjugations.
