Translation guide
The English verb 'is' (the copula) has no single direct equivalent in Japanese. The correct expression depends on what is being described: identity, property, location, existence, or a grammatical pattern. This guide covers the most common ways to express 'is' in natural Japanese.
A is B (i-adjective).
I-adjectives already contain the copula; do not add だ/です after the adjective.
The speaker wants to state that something is equivalent to or defined as something else (noun + copula).
The standard polite copula pattern. A is the topic, B is a noun or na-adjective. In plain speech, use だ instead of です.
Plain form of the copula. Used in casual speech, written language, and subordinate clauses.
He is a doctor.
Very formal/humble copula. Used in business or service contexts.
This is the conference room.
The speaker describes a property or state using an i-adjective. The copula is already built into the adjective.
I-adjectives end in い and function as predicates without an additional copula. Add です for politeness, but never add だ after an i-adjective in standard Japanese.
This cake is delicious.
The speaker states that something exists or is present. Japanese distinguishes animate vs. inanimate.
Used for inanimate objects, plants, and abstract things. Polite form of ある.
The speaker describes an ongoing action or a resulting state. English uses 'is' as an auxiliary.
The ている form covers both progressive actions and states resulting from a change. Polite form is ています.
The speaker describes an action done to the subject. English uses 'is' + past participle.
Japanese passive form. Often used when the subject is affected by an action, sometimes with a nuance of inconvenience.
The speaker asks whether something is equivalent to something else.
Add か to the polite copula to form a yes/no question. In casual speech, か is often dropped and replaced by rising intonation or の.
Is this your umbrella?
The speaker emphasizes or explains a situation, similar to 'It is that...' or 'The thing is...'.
Nominalizer の + copula. Used to explain or emphasize a reason or fact.
What is important is health.
In very casual conversation, the copula is often dropped, especially by women or in certain dialects.
In informal speech, ending a sentence with a noun or na-adjective stem without だ/です can sound softer or more feminine. Not recommended for beginners.
Dropping the copula can sound abrupt or feminine depending on context. Use with care.
This is a book.
I-adjectives already contain the copula. Saying おいしいだ is ungrammatical. The polite form is おいしいです, and the plain form is simply おいしい.
This ramen is delicious.
Use ある for inanimate objects, plants, and abstract concepts. Use いる for people, animals, and sometimes robots or dolls perceived as animate. When in doubt, ある is safer for non-living things.
今日は暑い。
Today is hot.
Negative form of i-adjectives. ～くありません is more formal, ～くないです is common in speech.
This room is not spacious.
There is a book on the desk.
Used for people, animals, and other animate beings. Polite form of いる.
There is a child in the park.
Pattern for 'A is located in/at B'. Use に for the location.
The station is over there.
The cat is in the room.
He is reading a book now.
The window is open.
This book is read by many people.
Used to define or explain the meaning of a term.
'Arigatou' is a word of thanks.
机がある。
There is a desk.
There is a dog.
です is the polite form of the copula and can be attached to i-adjectives and nouns. In formal writing, である is often used instead of だ.
The sky is blue.
There is a cat in the garden.
Is this seat taken?