tomodachi ga kireina utagoe de utaikiru to, ookina hakushu ga okotta.

When my friend sang all the way through in a beautiful voice, loud applause broke out.

Breakdown of tomodachi ga kireina utagoe de utaikiru to, ookina hakushu ga okotta.

• 友とも達だち: friend
• が: subject particle
• で: means particle
• と: conditional particle

Questions & Answers about tomodachi ga kireina utagoe de utaikiru to, ookina hakushu ga okotta.

Why is 友達 marked with が instead of は?

が marks 友達 as the subject of 歌い切る: the friend is the one who finishes singing.

Using は would make 友達 the topic instead, which would slightly change the feel:

• 友達が = focusing on the friend as the subject
• 友達は = as for my/the friend...

In this sentence, が works well because the sentence is narrating an event: the friend sang, and then applause happened.

Why is it きれいな歌声 and not きれいい歌声 or きれいの歌声?

きれい is a な-adjective, not an い-adjective, even though it ends in -い.

So:

• before a noun: きれいな歌声
• at the end of a sentence: 歌声がきれいだ

That is why you need な before 歌声.

What exactly does 歌声 mean here?