neko ha riido ga suki de ha naku, sugu nigeyou to simasita.

は marks 猫 as the topic of the sentence: As for the cat...

That sets up the rest of the sentence as information about the cat. It does not mean the cat is doing a strong contrast here; it is just the main topic.

It also helps explain the second part of the sentence. In すぐ逃げようとしました, the subject is omitted, but we naturally understand it as the cat, because 猫は already established the topic.

Because 好き is not used like a normal action verb such as 食べる or 見る.

好き is a na-adjective (or adjectival noun), and the thing that is liked is often marked with が.

So:

• 猫はリードが好きだ = The cat likes the leash.
• not normally 猫はリードを好きだ

A very literal way to think about it is:

• リードが好き = the leash is pleasing / likable to the cat

That is why が appears here.

好き is usually treated as a na-adjective.

That is why it behaves differently from a verb:

• positive: 好きだ
• polite: 好きです
• negative: 好きではない
• connective negative: 好きではなく

So in this sentence, 好きではなく is not a verb form like 食べなく or 行かなく. It is the negative connective form built from 好き plus the copula pattern.

好きではなく is the connective negative form of 好きだ.

Break it down like this:

• 好きだ = is liked / likes
• 好きではない = is not liked / does not like
• 好きではなく = not liking..., and...

In this sentence, it links to what happens next:

• 猫はリードが好きではなく、すぐ逃げようとしました。

So the meaning is roughly:

• The cat did not like the leash, and tried to run away right away.

The なく form connects the first idea to the second.

Both can connect ideas, but ではなく sounds a bit more written or formal, while ではなくて sounds a bit more conversational.

So:

• 好きではなく、すぐ逃げようとしました = slightly more written/narrative
• 好きではなくて、すぐ逃げようとしました = more speech-like
• 好きじゃなくて = even more casual

All are possible depending on style. The version in your sentence is perfectly natural in written narration.

逃げよう is the volitional form of 逃げる.

• dictionary form: 逃げる = to run away / escape
• volitional form: 逃げよう = let’s run away / I’ll run away / about to try to run away

By itself, 逃げよう often expresses intention or suggestion. But in this sentence it appears in the grammar pattern:

• volitional form + とする

So here it is not simply Let’s run away. It is part of 逃げようとしました, meaning tried to run away.

逃げようとしました means tried to run away.

It is built like this:

• 逃げよう = volitional form of 逃げる
• とする = to attempt to do / to be about to do
• としました = past tense

So:

• 逃げようとしました = tried to run away

This pattern often shows an attempt that may or may not have succeeded. It focuses on the effort or intention, not the result.

This と is part of the grammar pattern volitional + とする.

It is related to the quotative と, as if the person or animal is internally going I’ll run away and then acting on that intention.

So:

• 逃げようとする = to try to run away
• 食べようとする = to try to eat
• 出ようとする = to try to leave

You should learn V-volitional + とする as a set pattern.

Because Japanese often omits subjects when they are already clear from context.

The sentence begins with 猫は, so once the cat is established as the topic, the second clause does not need to repeat it:

• 猫は リードが好きではなく、(猫は) すぐ逃げようとしました。

In English, we usually repeat the cat or it, but Japanese often leaves it out.

すぐ means immediately, right away, or soon.

Here it modifies the action 逃げようとしました:

• すぐ逃げようとしました = tried to run away immediately / right away

So the flow is:

1. the cat did not like the leash
2. as a result, it immediately tried to run away

Yes. In pet-related Japanese, リード commonly means leash.

It is a loanword, and in this context it does not mean the English verb lead in a general sense. It specifically refers to the strap or lead used for walking an animal.

So 猫はリードが好きではなく means the cat did not like the leash.

Yes, but the nuance changes.

• リードが好きではなく = neutral statement that the cat does not like the leash
• リードは好きではなく = contrastive nuance, something like it doesn’t like the leash, at least

Using は on リード would suggest some contrast, whether stated or unstated:

• maybe it likes the collar, but not the leash
• maybe it likes being outside, but not the leash

So in a plain sentence, が is the more neutral choice.