kono uta wo utaikitta.

歌い切った means something like finished singing it completely or sang it all the way through.

The difference is:

• 歌った = sang
• 歌い切った = sang completely / finished singing

The 切る part adds a sense of completion. It often suggests that the action was carried through to the end, sometimes with effort or a feeling of accomplishment.

So この歌を歌い切った is stronger than just この歌を歌った.

It is made from:

• 歌う = to sing
• 歌い = the stem of 歌う
• 切る = to cut, but here it works like a helper verb meaning to do something completely
• 切った = past tense of 切る

So:

• 歌う → 歌い
• 歌い + 切る → 歌い切る
• 歌い切る → 歌い切った (past)

This is a very common pattern in Japanese:

• 読み切る = read all the way through / finish reading
• 使い切る = use up completely
• やり切る = carry through to the end

Because when one verb connects to another verb like this, Japanese usually uses the verb stem.

For 歌う, the stem is 歌い.

So:

• dictionary form: 歌う
• stem: 歌い

Then the second verb is attached:

• 歌い切る

This happens with many verbs:

• 読み
  • 切る → 読み切る
• 食べ
  • 切る → 食べ切る

Not really. In this sentence, 切る is not being used in its literal meaning to cut.

Instead, it is acting as an auxiliary-like verb that adds the meaning:

• completely
• all the way
• to the finish

So in 歌い切る, 切る means something like finish completely, not cut.

This kind of meaning extension is very common in Japanese.

を marks the direct object of the verb.

Here, 歌 is the thing being sung, so it takes を:

• この歌を歌い切った
• I finished singing this song

Even though 歌 and 歌う are closely related in meaning, Japanese still treats the noun song as the object of the verb sing.

So this is completely normal:

• 歌を歌う = sing a song

It can feel repetitive to an English speaker, but it is normal in Japanese.

• 歌 = song
• 歌う = to sing

So 歌を歌う literally looks like sing a song, which is perfectly acceptable.

Japanese often uses related noun-verb combinations like this. It does not sound strange in the way song sing might sound if translated too literally.

この means this, and it directly modifies the noun that follows it.

So:

• この歌 = this song

You do not use の here, because この is already a determiner that goes directly before a noun.

Compare:

• この歌 = this song
• あの歌 = that song
• どの歌 = which song

The subject is omitted, which is very common in Japanese.

So この歌を歌い切った does not explicitly say:

• I finished singing this song
• She finished singing this song
• We finished singing this song

Japanese often leaves that to context.

In a real conversation, the listener usually already knows who the sentence is about.

歌い切った is plain past.

The polite version would be:

• この歌を歌い切りました。

So:

• 歌い切った = plain past
• 歌い切りました = polite past

The meaning is the same, but the level of politeness is different.

Often, yes.

The 〜切る pattern frequently suggests not just completion, but completion despite difficulty, or at least a sense of seeing something through.

So 歌い切った can imply things like:

• the song was long
• the song was difficult
• the speaker is proud to have finished it
• it took stamina or determination

That nuance depends on context, but it is often present.

No. Normal Japanese writing usually does not use spaces between words.

It would normally be written as:

• この歌を歌い切った。

The spaces are often added in teaching materials to make the sentence easier for learners to read.

So the spaced version is for learning, not standard writing.