isogashii node, tomodachi no messeeji dake saki ni kidoku ni shite, henji wa ato de kakimasu.

Because I’m busy, I’ll mark only my friend’s message as read first, and write a reply later.

Breakdown of isogashii node, tomodachi no messeeji dake saki ni kidoku ni shite, henji wa ato de kakimasu.

• は: topic particle
• 友とも達だち: friend
• の: possessive case particle

Questions & Answers about isogashii node, tomodachi no messeeji dake saki ni kidoku ni shite, henji wa ato de kakimasu.

What does ので do here, and how is it different from から?

ので gives a reason: because / since.

• 忙しいので = because I’m busy
• The sentence is explaining the reason for the actions that follow.

Compared with から, ので usually sounds a bit more neutral, softer, and more explanatory.

• 忙しいから、… = because I’m busy...
• 忙しいので、… = because I’m busy... (slightly more formal or gentle)

Both are possible, but ので fits well in calm explanations like this.

Why is it 忙しいので and not 忙しいだので or 忙しいなので?

Because 忙しい is an い-adjective.

With い-adjectives, you attach ので directly:

• 忙しいので

You do not add だ or な.

Compare:

• 忙しいので = because it’s busy / because I’m busy
• 学生なので = because I’m a student
• 静かなので = because it’s quiet

So:

• い-adjective → 忙しいので
• noun / な-adjective → 〜なので

What does 友達のメッセージ mean exactly? Is it my friend’s message or a message from my friend?