neko ga soto ni detagatte iru keredo, ame ga hurisou dakara kyou ha dasanai.

Because the sentence is describing the cat’s apparent desire, not the speaker’s own desire.

• 〜たい is most naturally used for your own desires:
  • 外に出たい。 = I want to go outside.
• For a third person’s desire, Japanese often uses 〜たがる:
  • 猫が外に出たがる。 = The cat wants to go outside / acts like it wants to go outside.

Then 〜ている is added:

• 出たがっている = is showing signs of wanting to go out
• This can imply an ongoing state, like the cat is currently scratching at the door, meowing, waiting by the door, etc.

So 出たがっている is more natural than 出たい when talking about a cat.

It breaks down like this:

• 出る = to go out
• 出たい = want to go out
• 〜たい becomes 〜たがる when talking about someone else’s desire
• 出たがる = to show signs of wanting to go out
• 出たがって = て-form
• 出たがっている = is showing signs of wanting to go out

So:

• 猫が外に出たがっている = The cat wants to go outside
  more literally: = The cat is acting as if it wants to go outside

Here, が marks 猫 as the subject of 出たがっている.

• 猫が外に出たがっている = The cat is the one wanting to go outside

Using は is also possible in some contexts, but it changes the nuance.

• 猫は外に出たがっている can sound more like:
  • As for the cat, it wants to go outside
  • perhaps setting the cat up as the topic

In this sentence, 猫が feels natural because the speaker is simply stating what the cat is doing/wanting.

Because 外に出る is the standard pattern for go out(side).

• 外 = outside
• 出る = go out / come out
• に marks the destination or resulting location

So:

• 外に出る = go outside

This is a very common expression. Even though English uses outside like an adverb, Japanese often treats 外 more like a noun, so に is natural.

Yes, here けれど means but / although.

It connects the two parts:

• 猫が外に出たがっているけれど = The cat wants to go outside, but...

Compared with でも, けど, or が, けれど is a neutral, common connector.

It often sounds a little softer than a very direct but in English.

It may feel a little unusual from an English point of view, but in Japanese this is perfectly natural.

The structure is:

• 猫が外に出たがっているけれど = The cat wants to go outside, but...
• 雨が降りそうだから = because it looks like it’s going to rain
• 今日は出さない = I’m not letting it out today

So the whole logic is:

• The cat wants to go out, but because it looks like rain, I’m not letting it out today.

Japanese often layers connectors like this very naturally.

降りそう means looks like it’s going to rain.

It comes from:

• 降る = to fall, to rain
• 〜そう = looks like / seems likely to

So:

• 雨が降りそう = It looks like it’s going to rain

This そう is based on appearance or immediate likelihood.

No, this is a different そう.

There are two very common そう patterns:

1. Appearance-based そう

   • 雨が降りそう
   • It looks like it’s going to rain

2. Hearsay そうだ

   • 雨が降るそうだ
   • I heard that it will rain

Notice the difference:

• 降りそう = seems likely, based on how things look
• 降るそうだ = apparently / I heard that it will rain

In your sentence, it is the appearance-based one.

Good question. 出る is intransitive, but 出す is transitive.

• 出る = to go out
• 出す = to put out / let out / take out

So here:

• 今日は出さない means I won’t let [the cat] out today

The speaker is not saying the cat itself won’t go out on its own. The speaker is saying they will not let the cat go out.

That fits the context much better.

The object is omitted because it is obvious from context.

Earlier, the sentence already introduced the cat:

• 猫が外に出たがっている

So when the speaker says:

• 今日は出さない

the omitted object is understood as the cat.

In fuller Japanese, you could say something like:

• 今日は猫を出さない。

But once the cat is already the topic of discussion, leaving it out is very natural.

は gives 今日 a topic or contrastive feeling.

• 今日は出さない = As for today, I’m not letting it out = I’m not letting it out today

This can imply contrast, such as:

• maybe on other days the cat is allowed out
• but today, because of the weather, it isn’t

Without は, 今日出さない is possible, but 今日は sounds more natural here because the speaker is setting today apart from other days.

Yes, the understood subject is most likely I or we, depending on context.

Japanese often omits subjects when they are clear. In this sentence:

• the cat wants to go out
• it looks like rain
• so [I] won’t let it out today

A natural English translation often needs to add I, even though Japanese does not say it explicitly.

You could translate it that way literally, but it sounds less natural in English.

A better natural translation is:

• The cat wants to go outside, but it looks like it’s going to rain, so I’m not letting it out today.

If you want to reflect the nuance of 出たがっている more closely, you could say:

• The cat is acting like it wants to go outside...
• The cat seems to want to go outside...

Those versions capture the Japanese nuance especially well.

It is fairly neutral and common.

Very roughly:

• けど = more casual
• けれど = neutral
• けれども = a bit more formal or careful

So in this sentence, けれど sounds natural and standard.

No, not with the same meaning.

• 出たがっている comes from 出る = to go out
• 出したがる would come from 出す = to put out / let out / take out

So:

• 猫が外に出たがっている = The cat wants to go outside

But 出したがっている would suggest wanting to put something out or let something out, which is not what the cat wants here.

So 出たがっている is correct.