Learn Hardcore Japanese: kore ha neko desu.

The particle は (pronounced wa when used as a particle) marks これ as the topic of the sentence. It tells the listener “we’re talking about this.”
– Written as は, pronounced wa in this role.

Is は always a topic marker? How is it different from が?

– は introduces or contrasts topics: “As for X, …”
– が marks the grammatical subject or highlights new information.
Example:

これは猫です。 (This is a cat—introducing “this.”)
これが猫です。 (This here is the very thing that is a cat—emphasizing identification.)

Why isn’t there a particle after 猫?

Because です follows directly after the noun to form the copula “is.” In Japanese, you don’t need another particle between the noun and です when you’re simply stating “X is Y.”

What exactly is です and why do we need it?

です is the polite copula, equivalent to “is/am/are.” It makes the sentence polite rather than plain. Without it, the sentence would sound rough or incomplete in polite conversation.

What is the basic word order demonstrated here?

The pattern is:

Topic (これ)
Topic marker (は)
Predicate noun (猫)
Copula (です)
Japanese typically follows Topic–Comment order, roughly SOV (Subject/Topic–Object–Verb).

How do you turn これは猫です。 into a question?

Add the question particle か at the end:
これは猫ですか？
This becomes “Is this a cat?”

Can you omit これ or です in casual speech?

– これ can sometimes be dropped if the context is clear.
– です can be dropped in very casual speech, making it “これは猫.” However, this sounds informal and might be too blunt in polite settings.

How would you say “those are cats” using this structure?

Use the demonstrative それ (those near listener) or あれ (those farther from both):

それは猫です。 (Those are cats—near you.)
あれは猫です。 (Those are cats—over there.)

Does 猫 change for plural (cats) like English?

No, 猫 can mean “cat” or “cats.” Japanese often relies on context or adds words like たち (e.g., 猫たち) if you explicitly want to emphasize plurality.