sore ha burahu datta.

それ means that or it, depending on the context.

In this sentence, it points to something already mentioned, understood from the situation, or associated with the listener’s side of the conversation. In natural English, it could be translated as either that or it.

Related words:

• これ = this
• それ = that
• あれ = that over there

So それ is a very common way to refer back to something someone just said or did.

は marks the topic of the sentence.

So それは means as for that... or that... as the thing being talked about.

The basic pattern here is:

X は Y だった
= X was Y

So:

それはブラフだった。
= That was a bluff.

A helpful point: は is not exactly the same as the English subject marker. It introduces what the sentence is about.

ブラフ is written in katakana because it is a loanword, borrowed from English bluff.

Katakana is commonly used for:

• foreign loanwords
• onomatopoeia
• emphasis
• some names and technical terms

So seeing katakana here tells you this is not a native Japanese word, but a word adapted from another language.

It is pronounced roughly bu-ra-fu, but the u sounds are often light in natural speech.

So it may sound closer to:

burafu

A few pronunciation notes:

• ブ = bu
• ラ = ra
• フ = fu

Japanese pronunciation does not match English bluff exactly. The final フ is the standard Japanese way to approximate that final sound.

だった is the plain past form of だ, the casual copula.

You can think of it as the part that makes the sentence mean was.

So:

• だ = is / am / are in a casual noun sentence
• だった = was / were in a casual noun sentence

Examples:

• 学生だ。 = I’m / he’s / she’s a student.
• 学生だった。 = I was / he was / she was a student.

Here:

• ブラフだ = it is a bluff
• ブラフだった = it was a bluff

Because ブラフ is the predicate noun of the sentence.

This sentence follows a simple noun sentence pattern:

それ + は + ブラフ + だった
topic + topic marker + noun predicate + past copula

So ブラフ is not an object here. It is what それ is being identified as.

That is why you do not need a particle like を after ブラフ.

They both express past tense, but the difference is formality.

• だった = plain / casual
• でした = polite

So:

• それはブラフだった。 = casual
• それはブラフでした。 = polite

Both mean the same basic thing. The choice depends on who you are speaking to.

Use だった with:

• friends
• casual conversation
• narration
• internal thoughts

Use でした with:

• teachers
• strangers
• formal situations
• customer service situations

Yes, but the meaning changes slightly because the tense changes.

• それはブラフです。 = It is a bluff.
• それはブラフでした。 = It was a bluff.
• それはブラフだった。 = It was a bluff. (casual)

So if you are talking about something in the present or making a present judgment, です works. If you are referring to something as past, use でした or だった.

Yes, it is completely natural and complete.

Japanese often leaves out information that is obvious from context. Even though the sentence is short, it can stand on its own if everyone already knows what それ refers to.

For example, それ could refer to:

• a statement
• a threat
• a plan
• a move in a game
• a negotiation tactic

That kind of context dependence is very normal in Japanese.

The difference is mainly about focus and information structure.

• それはブラフだった。
  = As for that, it was a bluff.
  This is the more neutral sentence if you are simply talking about that as the topic.

• それがブラフだった。
  = That was the bluff / That was what turned out to be a bluff
  This can sound more identifying or emphatic, depending on context.

In many situations, は is the more natural choice when you are just stating what something was.

It is very similar, but not always identical in nuance.

In Japanese, ブラフ usually means some kind of:

• bluff
• fake-out
• deceptive move
• empty threat
• strategic lie meant to influence someone

It can be used in games like poker, but also in broader situations such as business, arguments, or strategy.

So the core idea is the same as English bluff, but the exact range depends on context.

The spaces are just for readability, usually for learners.

Normal Japanese would write this as:

それはブラフだった。

Japanese is normally written without spaces between words. So if you see spaces in learning materials, they are there to help you identify the parts of the sentence more easily.