kono eiga no saigo ha kanasii desu.

この must be followed by a noun, so この映画 means this movie.

• この = this + noun
• これ = this (by itself)

So:

• この映画 = this movie
• これ = this

You cannot say これ映画 in standard Japanese.

Here の links two nouns together. It often works like of or an apostrophe-s in English.

• 映画 = movie
• 最後 = end / ending / final part
• 映画の最後 = the movie’s ending / the end of the movie

So の shows that 最後 belongs to or is connected with 映画.

は marks the topic of the sentence.

So in:

この映画の最後は悲しいです。

the topic is この映画の最後 = the ending of this movie.

The sentence is basically saying:

• As for the ending of this movie, it is sad.

This is a very common Japanese pattern:

• A は B です = As for A, it is B.

Both は and が can sometimes seem possible, but they do different things.

In this sentence, は is natural because the speaker is talking about the ending of this movie as the topic and then describing it.

• 最後は悲しいです = As for the ending, it’s sad.

If you used が, it would sound more like identifying or emphasizing that the ending is the thing that is sad:

• この映画の最後が悲しいです

This is not impossible, but は is more natural for a simple descriptive statement like this.

悲しい is an i-adjective, meaning sad.

In Japanese, i-adjectives can already function as predicates:

• 悲しい。 = It is sad.

Adding です makes it more polite:

• 悲しいです。 = It is sad. / It’s sad.

So です here adds politeness. It does not turn 悲しい into a noun or change its basic meaning.

Because 悲しい is an i-adjective.

With i-adjectives:

• plain: 悲しい
• polite: 悲しいです

You do not add だ after an i-adjective.

Compare:

• 静かだ = quiet (na-adjective + だ)
• 悲しい = sad (i-adjective, no だ)

So:

• 悲しいです = correct
• 悲しいだ = incorrect
• 悲しいですだ = incorrect

最後 literally means last, final, or end, depending on context.

In this sentence, 映画の最後 naturally means:

• the end of the movie
• the ending of the movie
• the final part of the movie

So even though 最後 by itself is not exactly the same as the English word ending in every context, here that is the most natural meaning.

Yes, compared with English, Japanese word order is different.

English:

• The ending of this movie is sad.

Japanese:

• この映画の最後は悲しいです。
• literally: This movie’s ending, sad is.

Japanese often puts:

1. the topic first
2. the description at the end

So the important descriptive part, 悲しいです, comes at the end.

The spaces are only for learning purposes.

Normal Japanese is usually written without spaces:

この映画の最後は悲しいです。

Beginner materials often add spaces to make it easier to see the parts:

• この
• 映画
• の
• 最後
• は
• 悲しい
• です

But in real Japanese writing, you normally would not write it with spaces.

Not exactly. The sentence specifically says that the ending is sad, not necessarily the whole movie.

• この映画の最後は悲しいです。 = The ending of this movie is sad.

If you wanted to say This movie is sad, you would say:

• この映画は悲しいです。

That changes the topic from the ending to the movie itself.

Yes. In Japanese, 悲しい can describe not only a person’s feeling but also something that causes sadness or has a sad emotional quality.

So 悲しい ending is perfectly natural in Japanese:

• 悲しい最後
• 最後は悲しいです

In English, we often distinguish:

• sad = feeling sad / emotionally sad
• sad ending = an ending that makes you feel sad

Japanese 悲しい can cover both kinds of usage.

Yes, both are possible, but they have slightly different nuance.

• この映画の最後は悲しいです。
  A natural neutral statement: The ending of this movie is sad.

• この映画の最後が悲しいです。
  Puts more focus on the ending as the thing that is sad.

• この映画は最後が悲しいです。
  As for this movie, the ending is sad.
  This structure is also natural, especially if you are talking about the movie as a whole and then specifying what about it is sad.

So the original sentence is a very standard and natural way to say it.

You can simply drop です:

この映画の最後は悲しい。

That is the casual/plain form.

Compare:

• polite: この映画の最後は悲しいです。
• casual: この映画の最後は悲しい。

Both mean the same thing, but the first is more polite.