sakki ookina kaminari no oto ga shite, sukoshi kowakatta desu.

A little while ago there was a loud sound of thunder, and it was a little scary.

Breakdown of sakki ookina kaminari no oto ga shite, sukoshi kowakatta desu.

• です: to be
• が: subject particle
• の: possessive case particle
• 音おと: sound

Questions & Answers about sakki ookina kaminari no oto ga shite, sukoshi kowakatta desu.

Why is 大きな used instead of 大きい?

Both 大きい and 大きな can come before a noun, but they are used a little differently.

• 大きい is the regular -い adjective
• 大きな is a special form used only directly before a noun

In this sentence, 大きな雷の音 means a loud/big sound of thunder.

With 音, 大きな音 is very common and natural. It often feels a bit more descriptive than 大きい音, though both are possible in many situations.

What exactly does 雷の音 mean?

雷の音 literally means the sound of thunder.

Breakdown:

• 雷 = thunder, or the thunder/lightning phenomenon in general
• の = links nouns, like of
• 音 = sound

So this part is focusing specifically on the sound, not the flash of lightning.

Why is there a が after 音?

This is because 音がする is a very common Japanese pattern.

• 音がする = a sound is heard / there is a sound
• においがする = there is a smell
• 声がする = a voice is heard

Here, する does not mean to do. It means something more like to occur / to be sensed.

So:

• 雷の音がする = thunder can be heard / there is a sound of thunder

That is why が is used with 音 here.