tomodachi ga rusu datta node, rusuden ni messeeji o iremashita.

direct object particle

Breakdown of tomodachi ga rusu datta node, rusuden ni messeeji o iremashita.

• 友とも達だち: friend
• が: subject particle
• に: location particle

Questions & Answers about tomodachi ga rusu datta node, rusuden ni messeeji o iremashita.

Why are there spaces between the words? Is that normal Japanese writing?

No. In normal Japanese, this would usually be written without spaces:

友達が留守だったので、留守電にメッセージを入れました。

Textbooks and learning materials often add spaces to help beginners see the parts more clearly, but native Japanese writing normally does not separate words this way.

What does 留守 mean here?

留守（るす） means that someone is not home, away, or not present.

In this sentence, 友達が留守だった means the friend was absent / not there.

A useful thing to know is that 留守 is a noun, but in Japanese it can be used with the copula to describe a state:

• 留守だ = is away / is not home
• 留守だった = was away / was not home

So even though English might use an adjective-like expression, Japanese is using a noun + copula pattern.

Why is it 留守だった and not something like 留守でした or just 留守で?

留守だった is the plain past form of 留守だ.

• 留守だ = is away
• 留守だった = was away

Because it is followed by ので, the sentence needs the plain form before ので:

• 留守だったので = because the friend was away

You could also say , which is more polite and a bit more formal, but is very natural in everyday speech, especially when the final verb is polite: