kore wa hon desu.

this

Breakdown of kore wa hon desu.

• は: topic particle
• です: to be
• 本ほん: book

Questions & Answers about kore wa hon desu.

What does これ mean and what kind of word is it?

これ is a demonstrative pronoun meaning this (thing)—it stands in for a noun that is close to the speaker. In English we might say “this” on its own, but in Japanese これ replaces the noun entirely rather than modifying it.

Why is は used after これ, and what does it indicate?

は is the topic-marker particle. It tells us that これ (“this”) is what we’ll be talking about. A rough breakdown:

• これ (this) → topic of the sentence
• は marks “this” as the topic
  By marking “this” as the topic, the rest of the sentence comments on or describes it.

Why isn’t there a particle after 本? Shouldn’t every noun have a particle?

In a copular sentence of the form A は B です, B is simply the predicate noun (the complement of the copula) and doesn’t need an extra particle. Here’s the structure:

• Topic: これ は
• Predicate noun: 本
• Copula: です
  Since 本 is directly linked to です, no additional particle is required.

What is です, and why do we use it here?

です is the polite copula, equivalent to the English verb “to be” in its polite form. In これ は 本 です (“This is a book”), です:

• Links the topic to its description (“is”)
• Adds a polite tone (appropriate in most everyday situations)

Why can’t we use が instead of は in this sentence?

が marks the grammatical subject or the focus of new information, while は marks the topic (the thing you’re talking about). If you say これ が 本 です, it sounds like you’re emphasizing “this” as the one-and-only thing that is a book (e.g. answering “Which one is the book?”). By using は, you’re simply stating “As for this, it is a book,” which is the standard way to define or identify something.

Can I drop です and still be correct?

In casual speech you can replace です with the plain copula だ, or even omit it in very informal contexts. For example:

• Casual: これは本だ。
• Very informal (e.g. notes, slang): これ、本だ。
  However, in formal or polite situations you should keep です.

What’s the difference between これ and この?

• これ is a demonstrative pronoun: it stands alone and means “this (thing).”
• この is a demonstrative adjective (a prefix) that must modify a noun: it means “this [noun].”
  • この本 = “this book” (you need 本 after この)
  • これ = “this one/book” (no noun follows)

How do I make the sentence negative?

You can negate the copula. In polite speech:

• これは本ではありません。 (very polite)
  Or in more conversational style:
• これは本じゃないです。
• これは本じゃない。 (plain/casual)